Evil Mad Scientist Professor Brains sends his army of undead to invade various time periods and destroy the mankind for all eternity. It's up to Barry Steakfries, the badass Action Hero, to travel through time (Initially it was Prehistoric era, 1930's, Ancient Egypt, Ancient Japan and the Future, later updates and ports introduced 3 more chapters: Wild West, President Evilnote and Professor Brains' Lab) and put an end to the Zombie Apocalypse.
Player starts with a basic gun, but can get weapons from randomly-spawning crates, with power-up ranging from Shotguns and SMG's to Riffles and Flamethrowers. Additionally, there are Grenades, a secondary weapon, most useful against large groups of zombies, especially if you are cornered. You always start with 5 of them and need to constantly get them through specific weapon pickups. There are also few weapons that can replace them, such as Bazookas and Sentries.
The goal of each level is to defeat a huge amount of zombies coming from portals. Every third level features a boss, who will also be accompanied by hordes of the undead. At that point, they will keep spawning endlessly, so your goal changes to taking down boss' healthbar until they're finished.
Barry would later star in Monster Dash and Jetpack Joyride, both are canonically considered to be the prequels. The three game would spawn their own franchise. Barry, Professor Brains, and even Zombie T-Rex also appear in various crossovers by Halfbrick.
This video game provides examples of:
- Action Bomb: Red-glowing zombies will explode once you touch or shoot them.
- Announcer Chatter: Used for weapon pickups. With a different announcer per world, none the less.
- Autobots, Rock Out!: The entire soundtrack consists of metal-oriented themes.
- Bond One-Liner: Barry says several of them in the middle of slaughtering zombies in earliest versions. He also has some things to say after the round is over. Downplayed in level 5-2, where he starts running out of ideas.
- Cliffhanger: Eighth world, Brains' Lab, ends with Professor Brains announcing that he opened a portal to another dimensions and plans to invade another worlds. This was going to be followed by the series of crossovers with other works, before it was silently cancelled.
- Death Is a Slap on the Wrist: After losing a life, you respawn not far from where you died. Not only that, but the amount of lives you have always resets to the default 3 after completing the level, even if you had only one or two remaining. Getting a Game Over doesn't punish you much either, as you simply restart the level.
- Early-Installment Weirdness:
- Unlike Monster Dash and Jetpack Joyride, Age of Zombies is not an Endless Runner, but a top-dow twin stick shooter, with a proper ending. It also doesn't shy away from showing blood, instead of relying on Bloodless Carnage, especially noticeable with Monster Dash, where you still get to blast zombies and mummies in the face. Finally, the iconic Machine Gun Jetpack is completely absent.
- Originally, Barry was portrayed as a smoker and wasn't afraid of using heavy language (Never the F-word, though). Most of his dialogue and sprites were bowdlerised in the later ports.
- Flunky Boss: Every single boss battle is accomplained by an endless amount of mook zombies to keep you busy.
- Gatling Good: Minigun, the fastest bullet-firing weapon, although it decreases Barry's speed upon being used.
- Giant Mook: Some of the Zombies have bigger versions of themselves. They require more bullets to go down.
- Gratuitous Japanese: Ancient Japan announcer shouts weapons' names with a very heavy japanese accent. Barry also tries to speak Japanese in some of his dialogue.Barry: Nenrei zonbi no ruuru. Watashi wa subete watashi no tomodachi ni itteoku! My Japanese kicks ass.
- Noticing the Fourth Wall: Halfway through Brains' Lab, Professor Brains informs Barry that they are in a video game. Barry realizes that he knew he "had what takes to be the best game action hero of all time".
- One-Steve Limit: Subverted, as there's two Barrys: One is our protagonist, and the other is the Big Bad himself, Professor Barry Brains.
- One-Winged Angel: By fusing zombie powers with the future technology, Professor Brains transforms himself into a zombie mutant◊, which is a Final Boss of this game.
- Our Zombies Are Different: Regular Zombies, Caveman Zombies, Mafia Zombies, Mummy Zombies, Ninja Zombies, Robot Zombies, Washington Zombies and a Zombie Dinosaur.
- President Evil: Seventh world, which is even named after this trope, has Barry, dressed as Abraham Lincoln, killing an army of George Washington zombies, who are trying to destroy Independence Day.
- The Promise: After defeating the third boss, Barry teleports to another time era, before Prince Runningunnin could grant him immortality. Barry asks to find him in the future, which Prince does at the end of the fifth world.
- Regenerating Health: Barry's health slowly regenerates over time, so as long as you are not completely surrounded by zombies in every corner, you don't have to worry about being bitten by one.
- Resurrective Immortality: Prince Runningunnin is a member of Royal Consult, who live for over hundred years and can come back after being killed. He gives Barry the same powers after completing the fifth world, though he loses them in a Noodle Incident by the time sixth episode kicks in. Professor Brains seems to be this as well, being killed by Barry five times throughout the whole game. His first recovery was justified by him abusing time travel, while rest are implied to be him Exploiting the Fourth Wall.
- Shotguns Are Just Better: One of the collectable weapons is the SHOTGUN, very effective in the close range.
- Smart Bomb: Grenades are a downplayed example. They do not destroy every single zombie on the screen, but are limited in usage and are still very effective against a huge waves.
- Sprite/Polygon Mix: In 2014, there was a Season 2 update, which changed the game from 2D sprites to 3D models... Partially, that is, as the landscape and bosses all stayed in 2D. It was changed back very next year after a mixed reception.
- Stationary Boss: King Pharoah Shattinbricks, boss of the third world, who sits in his sarcophagus, throwing pink energy beams, fire balls and sickles at you.
- Your Head Asplode: What happens to King Shattinbricks after you defeat him.
- Zerg Rush: Individually, zombies are quite weak and don't take much health from Barry (plus, there's Regenerating Health). However, they can become a real threat due to their sheer amount. Being cornered by few of them means they'll chop off chunks of your health very quickly, which might make you lose a life. Get surrounded a huge wave of zombies with nowhere to run and you're a dead meat.