Anti-Climax Boss: The Egg Cannon in 4. It is possible to milk its chicken wave attacks for more powerups, and its laser, egg shell, and short laser streams attacks are easy to deal with. Its only attack that is the hardest is its three giant red energy bolts fired towards the player.
Averted in later updates for Universe and on higher difficulty missions in Universe, where it uses the attack introduced in the phase every time the fight advances to the next phase.
UFO enemies introduced in 4. While the chick-piloted UFOs drop a spread of two green poop and the chicken-piloted UFOs fire an egg at your ship, the real danger that comes from those enemies are that every time you knock their pilots out of their UFOs, the saucers will drop, meaning standing right under the destroyed UFOs can pose a danger if you don't shoot them down or move away from them quickly in time.
On the topic of UFOs, there are aliens piloting in UFOs that fire a blue laser. Not only they are hard to take down and then dropping their saucer when destroyed, their lasers are hard to react toward. Fortunately, they always give a warning before they attack, and only appear in the waves Shoot and Scoot, Nasty Surprise and Divide and Conquer, but those waves are made That One Wave as a result.
Chickenauts. While they are not very hard to take down with enough firepower, they fire a burst of 3 neutron bolts at random directions, making them unpredictable on higher difficulties. And it is possible to run into waves that feature a LOT of them on higher difficulty missions in Universe.
Ditto for Armored Chickens introduced in 5. Not only they are hard to take down, they fire a ring of 3 energy bolts at random directions periodically. Seeing plenty of those in a wave is an indication that you should be prepared for a tough time ahead.
Universe has introduced a good amount of enemies, and some of them prove to be quite dangerous:
Toxic Chickens leave behind a cloud of poison gas when destroyed, not too threatening when they are far from your ship, but depending on the wave's layout, like having them at the bottom of the screen or near your ship, they become very frightening to deal with due to their gas upon death.
Slob Chickens drop food every time you damage them, but occasionally they would fire a ring of poop on taking damage, making them unpredictable on higher difficulties. Absolver Beam remedies this by being a One-Hit Kill when strongly charged, preventing those enemies from dropping their poop rings as a result.
Chiller Chickens hurl snowballs aimed at you that won't destroy your ship on contact, but will instead seriously slow it down to 10% of the original speed, and will also obscure an a small area around your ship of the screen for a few seconds. Effects might have short duration, but getting slowed down can be extremely dangerous as that can render you unable to avoid projectiles, enemies and other hazards, especially when there are lots of them and when the snowballs move really fast on higher difficulties. The only good thing about them is that they will leave an cooling cloud that will prevent your weapons from generating heat while you are in it and shoot at enemies when they are killed.
Phoenix Chickens hurl fireballs that don't blow up your ship on contact, but instead overheat your ship and disabling your weapon, putting you out of action for a while and leave you more vulnerable to other attacks, which is bad news. Not helped by the fact the fireballs are aimed at you and move really fast on higher difficulties.
Coward Chickens introduced in Universe will always try to avoid your ship's line of sight, and when hit, they drop poop towards you. Refrain from using Scratch Damage weapons like Photon Swarm, and even though Plasma Rifle can One-Hit Kill those things, try not to channel the beam at targets near Cowards because the beam forms a nova that damages enemies around the target slightly, inviting the Cowards' streams of poop as a result of taking Scratch Damage! Absolver Beam is your best weapon for dealing with them as it can destroy enemy projectiles when fully charged.
Neutron Gun, one of the weapons you can get in early-game, has excellent damage output and slow heating rate, and in 2 when it reaches max power, its middle large bolt can One-Hit Kill a lot of enemies. Small wonder for why it is one of the more expensive weapons in Universe, as unlike many weapons barring Utensil Poker, it doesn't sacrifice damage output for increased likelihood of overheating.
Vulcan Chaingun in "Universe" not only has a very good damage output, but also can get a Spread Shot the longer you fire it, which makes it very good in waves that contain lots of enemies and hazards like What Time Is It, Comet Chase, Asteroid Vortex, Chicken Multiplicity, Chicken Exponentiality, etc. This is a double-edged tactic, however, as the spread may not be useful in waves with only few and lone enemies, additionally, you also need to be careful to not let it overheat while firing.
Plasma Rifle can One-Hit Kill many enemies once it reaches the middle levels of firepower, and even if you lost a life, you don't feel its power dwindled unlike many weapons, even on higher difficulties. The only drawback it has is a very fast overheating rate, which can be handled by proper heating management.
The secret weapon introduced in 3, Utensil Poker, has even better damage output than Neutron Gun, as well as the ability to occasionally fires forks as a spread shot. Add low heating rate in the mix and you have a weapon that virtually has no drawbacks, although one could argue that its drawbacks are the forks moving very slowly, and in Universe, massive weight.
Introduced in Universe, Absolver Beam requires you to hold the fire button to release a piercing laser, with its damage dependent on how long the fire button is held. Its pathetic damage output from rapid-fire shots force you to charge the laser for maximum damage, with its narrow range and very fast heating rate making it unideal for standard wave clearing. However, in certain waves involving single targets like Technological Advances and Armored Division, waves where chickens are packed in columns like Dazzling Coordination and Ultimate Extreme Square Dancing, and waves where chickens are bundled up into a pile like Bow Ties Are Cool and the newly introduced Tangled Mess, Absolver Beam shines in those waves by melting many chickens lined up in its crossfire swiftly. It excels at boss-clearing thanks to its piercing ability and being able to remove projectiles when strongly charged, which other normal weapons lack. It can stop certain bosses' attacks, like force fields and rotating lasers, by firing the strongly charged beam at its midpoint (you gotta memorize it, though) when they channel those attacks. Play your cards right when using this, and it can turn many bosses into a joke, especially those considered That One Boss (e.g. the Henperor's Apprentice, Bossa Nova, and the Supernova Core).
Photon Swarm in Universe can be this, as its widespread combined with homing allows you to kill enemies from an angle where they can’t reach you (as most projectiles are going straight down or up to 45 degree angle), so you remain safe most of the time. It also allows you to make narrow escapes from projectiles while continuously shooting the bosses. Works especially well with overdrive due to its low heating rate.
Corn Shotgun has a very high damage output that matches the damage output of Neutron Gun, Vulcan Chaingun, Plasma Rifle, Utensil Poker, good spread capabilities, and which can be fired continuously even while at max heat, albeit with the reduced damage. It is very powerful against most of the enemies, but has difiiculties against metallic enemies like Armored Chickens, UFO enemies and Chickenauts. Other drawbacks are that it's not very accurate and that it's rate of fire is low, especially on low firepower levels.
Goddamned Bats: Alchemist Chickens introduced in Universe always throw flasks at your location. You will not die from those flasks, but when they shatter, they will create a stasis field that will seriously slow you down while you are in it, making it harder for you to dodge enemies, projectiles and other hazards. They will stop attacking once all the flasks on their belt are broken. Alchemist Chickens also have much more health than regular Chickens, and are sometimes even more durable than Armored Chickens, UFO enemies and Chickenauts to the point that even strong weapons like Neutron Gun, Vulcan Chaingun, Plasma Rifle and Utensil Poker have difficulties to kill them in a single shot. One would have a much easier time to destroy Alchemist Chickens if they were to have Absolver Beam fully charged.
Quirky Work: This is a shmup series where you shoot chickens in space (and a literal turkey shoot in the fourthgame's Thanksgiving edition), which drop roasted chickens and burgers as well as weapon Power Ups in the form of presents, alongside the typical space shooter tropes of shooting down asteroids and random UFOs.
Vulcan Chaingun from 4 onwards was seen as inferior to Boron Railgun introduced in the same game. Universe not only improved its damage output, it also gave it the ability to turn into a makeshift Spread Shot by having its shots fire in increasingly random directions as heat levels rises, which can give it an edge in levels with multiple enemies and hazards like What Time Is It, Comet Chase, Asteroid Vortex, Chicken Multiplicity, Chicken Exponentiality, etc.
Once considered a weak Spread Shot weapon when Utensil Poker was introduced, Ion Blaster's shot type has been dramatically changed to make it fire similarly to its incarnation in the first game, and give it a high-powered shot at the center on higher firepower levels. While not as strong as Utensil Poker, Ion Blaster can still function as an Emergency Weapon for any wave in the event the player picks up an undesirable weapon.
Lightning Fryer and Positron Stream are given the ability to chain attack enemies to distinguish themselves from the most-of-the-time One-Hit Kill Plasma Rifle. Chaining gives these weapons a niche in the thrice-per-week Speed Races, missions where the game throws weak enemies and bosses at the player and have the player clear the mission as fast as possible, by having their streams to chain attack nearby enemies to finish waves of weak enemies faster.
Initially seen as a very weak weapon even on max power, and its niche in clearing supernova debris in 4 removed by buffing the debris' HP in Universe, Photon Swarm received a massive buff by allowing it to fire orange, high-powered photon particles on high firepower, which was restricted to max power, in addition to give it the ability to home in on nearby enemies. While still far from being a general purpose weapon like Utensil Poker and Neutron Gun, the buffs give Photon Swarm a niche in boss slaying, being able to take down some hard bosses like Bossa Nova and the Henterprise with ease.
Boron Railgun was seen as a weaker, less-likely-to-overheat version of Hypergun in 5, but Universe introduced a mechanic that have its power scale with heat level, making it a high skill weapon that rewards heat management for not exceeding the overheat level to keep its damage output going strong under high heat level territory, and good at taking on bosses as a result of the change in its mechanics as well.
Button Mashing is mandatory throughout the series if you want to rapid-fire your weapon. Not so much of a problem if you're rapid-fire-clicking your mouse, but can be annoying when playing with a keyboard or joystick. 3 introduced the ability to autofire by holding the button, at the cost of a lowered fire rate compared to mashing the fire button/mouse clicks, making autofire unreliable for high DPS. Furthered discouraged by the same game also introducing the Overheating mechanic, where autofiring raises the overheat level faster than just tap-firing.
Unlike bombs in most shoot'em ups, missiles travel to the center of the screen to explode. So if you want to use a missile ASAP to get yourself out of a corner, you must travel to the center to instantly detonate the missile... if you can get to the center in time without crashing into something. This applies to the ICBM satellites, which only explode if they hit something, and coupled with their ridiculously slow speed making them the last thing you want as a panic button.
The unlockable mines addresses the "travel to the center" problem of missiles by the explosion coming from your ship... at the cost of a fixed 1-second delay, making it unreliable as a panic button either.
Universe introduces multiple bomb-like secondary weapons that can be used in the place of missiles and mines, which addresses the problems of both. The Dimensional Phaseout trades the destructive capabilities of most secondary weapons for a generous period of invulnerability, the Shockwave Capacitator immediately removes all projectiles around the player ship, and the Clucker Bomb not only removes all projectiles immediately on use, but the subsequent cluster bombs also remove projectiles when they explode, making them perfect for stopping projectiles from spawning for a short period of time.
5 features unlockable options that impose restrictions in exchange for a high score multiplier, which include starting the game with one life, disabling extra lives, doubling the number of food items to gain a missile, and preventing the general firepower-increasing powerup from dropping from normal enemies. Starting a game with the former two restrictions enforces a run where dying immediately results in a game over, thus immediately qualifying for the Greatest Chicken Hunter of All-Time Award achievement if the game is completed with these two restrictions.
In Universe, you can start missions with only one life, with no satellites or secondary weapons (doing so awards the Medal of Extreme Unpreparedness achievement), and with customizable skill levels for missions, you can play missions with a 90-100% difficulty rating and a high skill modifier to play missions with a difficulty exceeding 100%.
Honourable "Either Brave or Stupid" Achievement Award requires completing a stage without collecting powerups. Since increasing your weapon level is mandatory in the early game, it is only recommended to go for this achievement when you're at max power, but due to how losing lives knocks your firepower down and can potentially drop you out of max power, you're more likely to hoard powerups in the event of an unlucky death dragging down your firepower than trying not to collect a single powerup.
Greatest Chicken Hunter of All-Time Award involves completing the game without losing a life. While the series' difficulty are tame by shmup standards, obtaining the achievement is still a paramount task considering you must survive all the 120 waves without dying once. The Superior Budget Thriftiness Commendation Medal involves completing the game without using missiles, though that one is slightly more doable given the unreliability of missiles and mines as a panic button.
Want to start a mission that enforces those two achievements in Universe? Medal of Extreme Unpreparedness got you covered, where you have to complete a mission without any items equipped, which includes secondary weapons and extra lives. With the major increase in difficulty compared to the previous games and no way to gain extra lives and missiles, have fun surviving a mission with only one life and no panic buttons.
Every Final Boss has one attack that is quite difficult to deal with:
In 2 The Mother-Hen Ship's targeted neutron bolt stream attack during the third and final battle. Notable is that it was the first case of a boss firing projectiles at the player in the series, where projectiles up to that point were either downward facing or in random directions via the Mother-Hen Ship's neutron bolt rings.
The Yolk-Star's downward facing lasers, which fire at random intervals and the cannons shuffling to another position after firing. Have fun moving back and forth to avoid standing underneath the cannons before they begin to fire while you worry about not getting rammed over by terminator chickens.
The Egg Cannon's giant red energy bolts that are aimed at the player.
The huge fireballs fired by the Henterprise during its third and final confrontation. If you're still pushing away the black feathers while it starts firing fireballs, prepare for a world of hurt.
Universe introduced new bosses which certain attacks are a pain to dodge:
Bossa Nova's crushing attacks are manageable if you can manipulate where its ring of debris will crush you. Not the case for when it extends its ring of debris all the way to the other end of the screen and return to its core, and even if it does give a warning before it does that attack, if you can't find an opening when the debris return to its core, you're screwed.
Through memorization, the Egg Cannon Cannon Cannon Cannonade's attacks are manageable, but the randomness of the gaps in its third phase's egg arcs means that it is difficult to predict the spread the egg arcs will be fired at.
Tear Jerker: The Game Over music in Ultimate Omelette is pretty depressing... This is downplayed with Revenge of the Yolk and Cluck of the Dark Side and averted entirely with the first game and The Next Wave.
