Some alien world is under attack by some weird meteor-like seed that releases bad bugs and and generally do bad things. Some wierd ship in space decides to react and releases 4 things (some bio-commandos) to deal with the infestation. That's it. Incredibly basic info about which is what or what is going on. After 1st mission briefing and later summary you should know that you are here to deal with baddies and keep local fauna at non 0 numbers (although it will not change the outcome of the game in any way if you do). That's all you need, as gameplay-wise it's solid TPP shooter with some platforming elements. You are in control of one of 4 genohunters, with ability to swap between them any time. You can give the other three some basic orders like go there, attack that or follow me. Not that you will use them to often as AI of your companions is rather competent, they rarely get stuck, have fantastic pathfinding and can handle themselves in a fight. Main gimmick of this game is mutation. As you kill and butcher bodies of enemies and neutral creeps you absorb their DNA. From that you can mutate your soldiers in various ways, including increased speed or jump height, getting bigger claws or other weapons or increasing your armour. That way you can either build a diverse team with skills that complement each other or try to go with a team that consists of only speed-jumping shooters, heavy bruisers or anything like that. Four things you start with are supposed to have some archetypical builds, like one dedicated to speed or other to fighting and tanking but it can be easily overwritten. It all seems nice and fantastic but this game has it's flaws, given it is rather old and not all mechanics dated that well. Even though game runs smoothly it have almost no tutorials or minimap so it can be confusing, and may get boring after another hour of shooting and following the "O" marker with no other explaination of what to do. I personally had a blast both then and now.
