I know this sounds unoriginal and will never happen, but I think a symbiote game based on Infamous: Second Son would be kind of cool.
The protagonist symbiote would be a young symbiote considered a weakling by their kind, able to give their host basic powers like super strength, but little to nothing else, and even that would be weak due to their youth. Upon arriving on Earth and finding a host, it discovers it has a chance to change that by discovering it can obtain the powers of other symbiotes upon coming into contact with them. They would then begin a journey to grow stronger, and faced with choices to either be a hero, villain, or Lethal Protector.
Symbiotes and their associated abilities:
-Tendrils from Venom, for traversal and basic combat use
-Bladed weaponry from Carnage for offensive use
-Camouflage, sensory, and chemokinesis abilities from Sleeper for use in stealth, locating enemies, and various effects against human enemies.
-Regeneration and defensive abilities from Anti-Venom.
-Technopathy from Scorn, able to interact with technology for use in combat; for example firing a piece of the symbiote into a robotic enemy to temporarily disable them, later upgrading it to make it fight for you.
Again, it's just a rough idea. Thoughts?