You gain access to a goo-like being called a Symbiote. Different Symbiotes can have various abilities. You can purchase any kind of Symbiote.
They can bond with their hosts as a suit, enhance their physique (strength, agility, etc), adapt to environments (survive in space), shapeshift (such as making tentacles from their own body or making weapons with them), they can amplify the powers of their hosts and are normally weak to fire and sound.
Symbiotes also love chocolate.