Appreciate the in-depth review. I think you are right, the dash needs better feedback and 'proper juice'. Especially since it's the only thing the player can do in combat. I don't really want to give the player any direct attacks, because it would make the game too easy and once all the skeletons were killed there is nothing that keeps the player on their toes anymore, having to remember where they are is part of the game design.
The 'bug' that you jump on top of tunnels is a necessity of the game, so players don't get stuck in colliders, or have to wait for a whole time jump in a dark tunnel without anything to do. I plan to extend the upper layer in the future, so it will feel more intentional and there will be more stuff to do and explore up there.
Thanks again for your feedback, it was really insightful!