Good use of mechanics and rules to fit theme. The feel is really smooth, it's so nice. Would love to try with sfx, music and more visual feedback.  The enemy types are interesting too!

Seen many variants of the health = ammo theme but yours was nicely done and really obvious, with nice varied enemies and clean art as well. However this really needs some feedback as I don't know when I get hit (some screenshake and sound fx?) and the ammo left is quite barely legible so I don't know when I'm in danger.

This game is very fun. It's simple and straight to the point. The ammo=health thing really prevents me from spamming and makes me think. I like how you have to go to where the enemy dies to pickup the health/ammo as that puts me at risk and adds more tension. The risk vs reward shopping is also neat. There are a lot of games this jam doing health=ammo, but I think this one does it best by adding in additional elements to make health=ammo actually matter. Nice stuff!

I like the concept when combined with the upgrade system. It really enhances that risk/reward feeling. I kinda feel like the fire rate upgrade shouldn't exist though. It's basically just a way to throw your life away faster and doesn't really seem to have much upside in the game currently. Also, as someone else noted, it is very easy to get stuck in the wall. I did it twice in a row and then spent the rest of my time playing actively avoiding walls.

The upgrade system really ties this together!

The dual (rather triple) purpose mechanic of the currency really ads to your game instead of taking away from it like a lot of entries. The upgrade system means there's a gamble when trying to decide between health and gaining power.  It furthermore incentivizes the player focus much more on aiming properly to avoid going low on health, and to have currency left over for upgrades.

The Aesthetic is also simple but nice! I think a good word for it would be 'sterile' but it definitely works for the game and you stick to it consistently. The only thing is that the currency can sometimes be hard to see when there's a lot on  the screen, so it might be better to be a little more visible, whether that be making it slight bigger or slightly more contrasting with the background white color.

Bug:

The walls can be "sticky" in a sense that once you touch them you can't move along them, and I got completely stuck and unable to get out a couple times. But I know how much of a bitch collisions can be especially under time constraints.

This is a tough game! I'm a sucker for challenges, so I had fun!