The art so far is fantastic (love the shine on the ice)! And the music too! Very atmospheric. Since you said you want to continue after the jam, here's my thoughts:
- I recommend making sure the music doesn't restart on death and just continuously plays. The hiccup is very distracting.
- If you're going to have very long rooms, I suggest implementing some kind of health bar or mid-room checkpoint system. The length of that room shown in your gif on a one-hit kill system is really brutal.
- Watch the unexpected deaths from above. Unless you're trying to troll the player, having enemies come from offscreen with no warning to kill them while they're jumping up is never fun. Since the character can't aim upwards, they don't really have any way to counteract it.
You have a solid base you can be proud of and I hope you achieve a faithful version after the jam!