I have really mixed feelings about this game. I am happy that you went this far, you made a playable game, did the art but in terms of gameplay and visuals I didn't really enjoy it. The art is super subjective, just not my vibe but I admit it has its own style but the gameplay feels empty. OK, I'm running around and shooting idk what and... thats it ?
Maybe with more time you would do more stuff but I can give my feedback on improvements based on what I see right now.
1. Either a tutorial or a story to tell player what is the goal and what we need to do. Even if you wouldn't end up implementing it, having a clear goal is important (imho)
2. While I was shooting the monsters, some white thingy was flying out of me towards enemies - I still don't know what it was
3. Damage feedback (Visual/Sound/HP Bar/what ever that fits). Otherwise its unclear am I taking damage and how much longer can I survive
I'm not saying you did a bad game, it just needs more polishing and some more content :) And congratulations on your first jam. Hope to see more new games from you!