Science is magic! Also yes, Chemistry, Genetics, Genetic Chemistry, I'd love to see stuff like that as a crafting or what-not system. Also we will need Pepto-Bimol for when I eat a bad Space Taco. "Pepto-Bismol - Space Strength!"
I think a permanent character upgrade is op, unless they all have side effects greater than the bonus, so that each is a sort of trade-off to accommodate different playstyles, and not just something that makes you better than other people.
I'm guessing the ones they showed was to heal you (the red one) and we don't yet know what the green one is.
But still possible, there was something on Terraria that could restore your mana. That's pretty much what "battery" is.
Whatever it is, it's probably something like an extra battery charge, not a syringe you inject into yourself.
How about cat's ears to "hear" things in dark areas aka make them glow like the hunter potion in Terraria? EDIT: How about every time the monsters make a sound, they flash green for about a second and then disappearing again?