Loved the style, and loved the chief mechanic! i beat the game (barely) on my second play-through, and i enjoyed every minute of it. I know you all are working on another game right now (which i'm very excited for!) but if you ever wanted to return to this idea, i'd love to see this Health = your Level/Attack/currency for upgrades in a multiplayer game. it would be fun to balance fighting each-other with upgrading yourself... i know its quite the band wagon but i could see this working even as a Battle Royal style game (which i don't even play) just because it would incentivize taking out opponents for their shperes and then finding Labs to upgrade yourself...
Anyway, all that to say I really enjoyed this game and plan on going back and beating it with other characters!