Evolva is a third-person action game developed by now defunct British studio Computer Artworks and released in June 2000. The player leads a team of 4 "genohunters" trying to save a distant planet and its indigenous animals from a parasitic alien species. Each of the genohunters can develop new abilities by incorporating and altering the DNA they've absorbed from the creatures they have killed. Genohunters can grow spider claws, jump like a frog, breathe fire, vomit flammable liquids, shoot explosive spores, scramble enemies' brains, spawn small alien offspring that injure enemies, etc. The game has 12 large levels populated with invading alien insect-like creatures known as the "parasite guardians", as well as various indigenous animals. Levels are spread through 3 continents with completely different environments, and each continent has a "boss" at the end which your team of genohunters must defeat using the newly acquired abilities.
How to follow mission objectives, replenish health & what happens when a Genohunter dies. Tutorial video from the CD version of the game.