Fragile Speedster: Rogues, Ninjas, Assassins. Adventurers (Champion Rogues in the sequel) have lower health than other champions.
Geo Effects: Each tower class can only be built on tiles of the corresponding terrain type. Additionally, there are high ground tiles (which increase range and damage and allow every kind of tower to be built on them), forests (which block a tile until you cut them down), and mana well tiles (which increase your mana gain).
The Goomba: Peasants, who have no special abilities whatsoever and only appear in the first few waves.
Invisibility Cloak: Ninjas and Iron Guards use one as soon as they're hit. Thankfully, they can only do this once.
Mana: Used by the Player Character for cutting wood/taking over structures, temporarily increasing firing rates (or causing mass fear in the sequel) or releasing deadly meteors on your enemies. Enemies in the first game use this for Status Buffs.
Mook Medic: Priests in the first game. The second game has Monks (heals others), Wizards (heals and provides a speed buff to Mooks around them), Priestesses (healing aura affects all units around them) and Cooks (can heal or give foes a Booze-Based Buff).
No Damage Run: In order to get a Brilliant rating for a mission, you cannot let any enemies touch a single gem.
No Sell: Paladins, Templars, and enraged Berserkers are immune to secondary status effects. Iron Guards are immune to fear.
Rocks Fall, Everyone Dies: If you have all your enemies in a small area and enough mana, you can take them out with a meteor.
RPG Elements: You get experience points for finishing a level. They can be spent for skills, which upgrade your towers with special powers, increase ressource generations, or have other beneficial effects.
As well, towers gain experience points and can take levels, allowing you to upgrade them during a round.
Rule of Three: There are three tower types (Crypts, Temples and Dens), each with a race powering these towers (Undead, Demons and Orcs), a corresponding terrain (Snow, Rock and Grass), spell (Frenzy/Fear, Meteor and Cut Out) and skill tree. Also, you gain three skill points per level.
Splash Damage: The ballista dens. Catapult Dens take this Up to Eleven- the projectile explodes into more exploding projectiles.
Splash Damage Abuse: Stealth Bypass type — If a visible enemy is within range, the Burning Temple will also hit - and probably One-Hit Kill - ninjas in its range.
Standard Status Effects: Inflicted by mid- to high-level towers of certain types, or scrolls. As well, for each tower category there's a skill which gives you a chance of inflicting another, special one.
Fear causes the victim to retreat in disorientation and panic.
Radiation increases the damage the victim takes from other attacks.
Poison Cloud deals damage over time to enemies (including stealthed ninjas) that pass through it.
Stasis prevents an enemy from moving/attacking for a short time.
Polymorph transforms an enemy into a chicken, removing all abilities except flight. Does not work on bosses.
Charm is a status that Amazons inflict on your towers, preventing the tower from attacking for 8 seconds.
Status Buff: Bards can provide temporary haste to allies, making them move twice as fast. This is very bad if used on Ninjas. Rogues and Adventurers in the sequel can give themselves haste, Wizards can haste and heal a whole group around them, Cooks can Haste and grant temporary fear protection.
Frenzy was changed into this for the sequel. Even time a tower kills an enemy, that tower gets an attack speed increase of 25%.
Unstable Equilibrium: The more a tower attacks enemies, the more experience it gets. This makes towers near the cave get less experience and causes them to be less likely to defeat enemies that penetrate too deep. The sequel averts this via the Home Front skill, which makes all towers gain passive experience over time so even those near your cave can get stronger.
Awesome yet Practical: Chilling crypts cause the enemy to run backwards (or forwards if holding a gem). It is possible to upgrade this feature so each attack has a greater chance of causing fear, which also increases the tower's range. And the attacks bounce, potentially causing two enemies to flee. The sequel up the awesomeness even further (see below)
One of the upgrades is an extra gem, essentially an extra life. However, the experience gain for a level is partly determined by how many gems remain, giving you slightly more experience per level for the rest of the game.
Beam Spam: Especially at the beginning of an enemy wave, when all the gathered crypt charges are released at once.
Damage-Increasing Debuff: The Evileye Tower's 'Radiation' effect increases damage taken by those afflicted with it by a percentage. Initially, it's 25%, but you can upgrade this up to a 50% increase. This does make enemy assassins easier to beat (and trivializes the rest except ninjas even more)
Fake Balance: The Demon skill tree is extremely weak, while the Undead skill tree is quite overpowered. Though the towers themselves are pretty well-balanced.
However.. this IS mitigated somewhat by every point in the Demon tree translating to a 1% damage increase, while each point in the Undead tree only giving a 1% range increase. For most towers, once range reaches a certain point, increasing it really stops being effective, especially as in a lot of levels, it will not appreciably increase the time it can hit an enemy.
The Demon skill tree is also almost the only way to obtain a Brilliant rating on any map that includes a Boss Ninja, because your options for killing a boss Ninja are 2: 1) get lucky enough for a fear/freeze on the only hit that lands before he stealths, or 2) Meteor it multiple times after he is stealthed. The last Champion Ninja in the final stage is especially bad, you'll need 5 minimum-cost, full strength meteors to defeat it.
Game-Breaking Bug: On the eBaums World version, there is an ad which sometimes pops up in the middle of the game and automatically ends it.
Smoke Out: The ninjas' special ability. And it takes a long time to wear off, long enough to bypass most parts of the smaller maps unharmed.
Tetris Effect: After playing, expect to see things from the game when closing your eyes, especially the homing magic orbs of the Crypts and those level up symbols.
Cursed Treasure 2 provides examples of:
Airborne Mook: Certain enemies can fly over water paths, allowing them to take a shortcut to your gems.
All Your Base Are Belong to Us: You can now use Cut Out to take over enemy structures. This trope applies to the Mook Maker structures- once taken over, the mooks stop and you get an income of gold every few seconds (unless it's a pirate ship, which sinks but gives you a lot of gold).
Animorphism: Kite Druids will turn into birds to move over water. The Eagle Druid is a champion version who transforms into an eagle.
Asshole Victim: The Archmage. If his flavour text is true, he's killed countless colleagues to rise to his position.
Asteroids Monster: Pirates release a parrot when killed. Smugglers release a monkey and two parrots when killed.
Awesome yet Practical: The Fear spell and Dreadful Crypts get an even better skill where fear causes an opponent to lose 5% of their max health per second afflicted.
Baleful Polymorph: Clicking a yellow scroll turns all non-boss enemies around it into chickens, disabling their special abilities except for flight.
The Berserker: The Berserk Champions. Once their health drops to 60%, they go into a rage, becoming immune to fear and side effects while becoming faster.
Cool Ship: The Pirate Flagship, which launches out Smoke Bombs to support its troops, as well as submerging to deploy divers. Once its health gets low enough, it "sinks", then appears upside down, launching three smoke bombs at one go.
Distracted by the Sexy: Your towers can get charmed by Amazons once their armor breaks, preventing them from attacking. Use a Fear Spell to remove this quickly.
Druid: One of the enemy types. They turn into birds to fly over water. The Arch Druid can turn himself into an invulnerable leafy tornado and send out eggs which hatch into Mooks.
Dungeon Bypass: Flying enemies can fly over water, taking a shortcut to your gems.
Early Bird Boss: The General, if you're going for a Brilliant rating. Appearing in the third stage, you probably have not enough skill points to take him on without leaking an enemy/defeating him once he Turns Red. Unless you grind, of course.
Elemental Embodiment: Thunder Elementals and Water Elementals. The former are fast, while the latter regenerate over time.
Grievous Bottley Harm: Taking over a tavern will cause it to throw empty bottles at nearby enemies, slowing them down.
Level Grinding: Vastly downplayed compared to the previous game: since experience is calculated on a percentage of the level's experience (which get increasingly higher), the easiest way to get skill points is to lose the highest level over and over, getting a level up every two or three attempts.
Lighthouse Point: An annoying enemy structure found in the Pirates of the Last Sea expansion. These can provide a speed buff to 3 enemies within a large range. Seizing it makes it hurt up to 3 enemies within range via continuous fire beams.
Luck-Based Mission: Level 20 if you're going for a Brilliant Rating. Two Mook Maker ships with LOADS of hitpoints, two speed-increasing lighthouses with a lot of hitpoints and a water path extremely near your cave for Divers. If the enemies fail to drop enough potions for usage of Cut Out, it's impossible to complete with Brilliant.
Mecha-Mooks: Iron Guards. These Champions are immune to fear, can fly, and have a cloaking ability like Ninjas!
Mook Maker: Certain structures can spawn Mooks at the start of a wave. Taking over most of them will allow you to gain gold every turn while stopping the Mooks.
Dendrologists can create dendroids, small walking trees.
Maniac Monkeys: Upon death, Smugglers release a monkey that is hell-bent on stealing your gems. Said monkey is fast and has more health than any normal enemy!
Not Completely Useless: The Infernal Magnet Skill drags your gems back to your cave if they are moved, which shouldn't happen if you're going for a Brilliant rating. Then you face the Barbarian Queen, who has an ability that drags your gems out of your cavenote They're still considered untouched unless an enemy touches them when they're outside.
One-Hit Kill: The "Bury Alive" Skill Tree gives all undead orbs a small chance of instantly killing an opponent. This even works on Champions, but not bosses.
Pirate Parrot: The pirate enemies have one, which they release upon death as a separate enemy.
Recursive Ammo: The Catapult Den has this, which allows it to deal a great amount of damage.
Smoke Out: Engineers will throw a smoke bomb ahead, which stealths all the units inside.
Tactical Suicide Boss: If the High Priest didn't sic his Templars to attack you, you'd never be able to break his invulnerable sanctuary via the Templars' swords.
The Pirate Flagship's own smoke bombs can be sent back to it for a good amount of damage.
Tennis Boss: The Pirate Flagship. It fires out bombs onto land, which explode into concealing smoke. Click the bombs before they blow up to send them back to the ship and damage it greatly.
Took a Level in Badass: The Demon Skill Tree. in the previous game, a number of its skills were useless due to being used for retrieval of crystals (when you shouldn't need to have any retrieved). The sequel fixes this, by giving it some useful skills like Frenzy and experience boosting.