Like the DT64 said, I think the game is interesting but balancing is an issue. Think he said what I wanted to say and you said you had no time so I won't say anything about that here.
Things I liked:
- Procedural generated map - It looks quite well done, especially the snaking paths that are already dug out.
- Keybinding - Not many jam games has it but its a nice addition.
Some other feedback I would give would be:
- Have another upgrade for the speed. Or have checkpoints. Feels quite slow now, and after playing the game a few times, I would imagine the player being tired of the top part of the level. As most of the time, the valuable ores are at the bottom and I wouldn't want to spend 30-50% of my oxygen just travelling down.
- Not sure why it's laggy when I surface on low oxygen.