Hello there,
What a cool game. It can feel challenging, but I think it is well balanced actually. Did complete it first try. Even is the core of your gameplay is quite common now in the game industry, I have fun times going through the levels. I really love your art here, enemies are basic but everything look so great. I'm just sad there are no audio tracks or sounds here because it is a very cool project.
The enemies' variants and capacities are also a cool think, maybe you should have made variants about their AI paths (e.g an enemy that actually try to go away and not go straight into the player).
I didn't know how your game was actually using the theme, but hey you'll need to finish it to understand what is the lie: fair enough, a bit easy but it still matches.
I had some issues with some colliders, sometimes you think you can go between objects but... nope lol. It's not that impacting at the moment with the way the levels are but it can be frustrating later on.
Oh and, for this type of game, I think it could need more player feedbacks. I mean, it's hard to understand you got damaged. Screen shaking, sprite animation, sounds, there are plenty of solutions to do so.
Overall I wanted to try this game so much and it has been a cool experience, thanks for that. You should continue this project in the long term, it could become something very nice and I would definitely play it.
Congratz man!