Deeep.io has you evolving into a variety of fish and animal forms as you gather food and explore the deeps and shallows of the sea. Each animal form comes with its own abilities and is optimized for different biomes, giving players a lot of variety as they slink around, hunt other deep-sea beasts, and explore what the oceans have to offer. 

You can play Deeeep.io aggressively like in another PVP style .io games, or you can evade conflict and just explore and try out the capabilities of each of the forms, giving you a fair amount of stuff to play with.