I agree with the other critiques about the new player friendliness of the game, it was definitely a challenge for me to figure out. However, I will say this is an awesome idea for a game! It's fun to be able to try to power yourself up, and then go fight the baddies with your juiced up form.
I think trying to work more detail about what everything does into the UI might help the game be more accessible. Maybe having some sort of animation showing the parasites being drained into the player might have helped, or having the syringe be smaller (or labeled?) I couldn't tell what it was until I watched the tutorial.
If possible, having somebody playtest who is totally new to the game seems to go a long way. I wish I would have done that more because there were a few times I shared my game with someone after it was completed and I regretted a few design choices because I realized it might be too hard for some players at first blush. We made our games, so we know exactly how everything works. Just because something is perfectly clear to us, doesn't mean it'll be clear to someone else.
I have to say, though, I don't know how many games you've completed outside GWJ but this is really an impressive first/early game to have made. Although it took some time to get comfortable with the mechanics, this demonstrates a lot of technical skill and I look forward to seeing you in future jams!