Move your soft, squishy, vulnerable body around with the [arrow] keys and jump with the [up] key. In a break with the Nitrome tradition of three-unit health bars, anything you touch will kill you. Your best survival strategy then, as a morally flexible space parasite, is to find a medium-sized creature and jump on its head, thrusting your tentacles into its skull and steering it around by tugging on its brain-meats. Ha ha ha haaaaa, fun!
Once you have enslaved a creature, press [Z] to use its unique ability (if it has one) and [X] to abandon it to live out the rest of its days in peace and prosperity. Or rather, to explode into chunks. Possibly peaceful ones.
Most of your victims will take one of three forms: a kitten with insect wings, a silverback bear-monkey, or a gob-horking pig. Most of the gameplay over the course of the game's 20 levels revolves around using the natural abilities of these creatures to overcome obstacles. For example, the kitty-fly not only serves as an air taxi, it can transport crates and other objects with its tail.
Analysis: Parasite is yet another great-looking game from Nitrome. Although the mainly purple-and-green background color scheme had a depressing effect on me over time, I could never get enough of the character animation. The purposeful slither of the alien, the clumsy toddle of the bear-monkey, the way your enslaved subjects drool with soulless malevolence — if you have even a touch of the arch-villain in you, this game will charm you down to the core of your thin, waxed mustache.
The central concept is so good, I wish that the level design supported it better. Having a bruiser, a helicopter, and a projectile vomiter at your disposal, you'd think there would be more puzzles involved. But Parasite mostly wallows in platforming and reflex challenges, sometimes the exact same challenges several times in a row. It's maddening to me that the pig's spitballs can rebound off of walls to hit difficult targets, but there are only two such targets in the entire game. That you get to ride an acorn like a guided missile, but the screen is too small for you to see oncoming hazards in time. And then there are three full levels about flying that horrible acorn. This game is an action platformer wearing the clothing of a puzzle platformer, and neither role fits comfortably.
There are enough moments of real ingenuity, though, that I can still recommend that you play some Parasite. When I drop an exploding bee hive on a pack of armored snails, or when I navigate a maze of wooden barriers and tunnels with a pair of zombie slave bears, I can feel the same kind of exuberance and love that went into Fat Cat or Final Ninja Zero (the same production team worked on all three games). The controls feel good enough, the lead character has a powerful presence, and the music does a nice trick where it gets sinister whenever you zombify a subject. All the pieces are here for an amazing game; they just need to be put together more cohesively. Here's hoping for a sequel.