Death screen wouldve really made this much better, I thought as a player, that I accidentally entered a new zone, and as such thought I was playing the same level over and over. Jump height should be increased slightly so that it clears the platforms much better. Theme was barely adhered to in my opinion, there was no reason for me to think that this was a cave instead of a dungeon, some indicators and visual cues that this is a dungeon wouldve helped. Needs audio, that goes without saying. Its good that you showed the player that tab is the build mode, except I think that the key should be shift, because the left most finger on the wasd cluster is already resting on shift. Build mode doesnt seem to have a clear use, I can just use ropes to traverse the levels. All of those aside, its really fun to play, and I wish it could have more visual feedback, some audio and perhaps some tuned controls.