Alright! I just played this game and would like to provide some feedback!!!
Overall the atmosphere is great. I really like the art and the overall concept. I got stuck in the same spot as CDelisa so I could not play much - (I'd love to play more!) but I have a few notes:
1. I LOVE DOUBLE JUMPING. The jump weight feels pretty good. However one thing you might consider is allowing a double jump to occur after a player has walked off an edge. Many times I would run off of a ledge before jumping off to gain momentum and then jump in the air but currently when this is done the jump amount is only 1. That makes some of the smaller platforms trickier to platform with. I'm assuming you may have a check to see if the player is on the ground and if so then jump, plus an integer count of 1 that counts how many in-air jumps you have. (or something along those lines) One idea would be to have a jump count that is reset when the player is grounded. Then walking off of a ledge a player could still have access to 2 jumps. (just an idea I thought of I'm sure there would be some adjusting to work with this game)
2. The sound effects are so eerie and awesome. Fantastic.
3. Seriously the sounds. I just remembered the gun fire sound and its neat.
4. The parallax is super cool. Sometimes it felt like it was moving too fast in regards to the foreground, but still it made the game feel huge. I think adding a vertical parallax in addition to the horizontal one would really be icing on the cake.
5. One thought is adding health bars to the enemies. I liked having to kite around but knowing how close I am to killing an enemy would help me make some riskier plays.
Seriously great job on this game. I just wanted to do a write up because I think it has a lot of potential! This was a big scope for a jam and I think you executed it very well. If you ever want to reach out and chat gamedev or anything let me know! Cheers!