This was a fun little game. The single resource worked well. Initially I was trying to shoot every enemy, until I realized I was not gaining anything from them. Then I reversed course and just tried to avoid all of them. I was so focused on movement, I forgot about the shield and had built up a lot of unused coins when I died. That run reached level 14 or 15. I didn't remember if I'd leveled up since last looking and the game over covers the level. I would move the game over down a bit so you can see your final level. My score was a bit over 4100. I only realized I should have been using the shield after losing, so I retried with the same strategy, except always keeping the shield up. I found that the shield is wider than you are and would get hit when you could have evaded with no damage, especially when squeezing along the edges, so that did require a bit more planing of my route. I managed to get to level 28 and a score of 5866 on that run. I don't think I fired a single shot in it. My level up started by focusing on movement then max HP and occasional heals. My final max HP was around 15.
I think the coin pickup collisions could be a bit more in the player's favor. I often missed a coin I thought I should have gotten. I think the camera angle was messing with my judgement a bit. On the other hand, the narrow collision area was in the player's favor for avoiding enemies.
With most of the game relying on keyboard for movement, it would be nice if the upgrade inputs did as well. Late game it was a bit jarring going when you leveled up, and then as soon as you clicked you had to go back to dodging with the keyboard.
Overall, a good jam submission.