That was very hard work but also very engaging! Nice puzzles with good learning curve, tricky level of precision required - which needs excellent control to feel "fair", so I docked half a star as the controls weren't always smooth (particularly if you want to start a level with a jump, for some reason).
I'm not sure the levels are in the right order as some of the later levels definitely felt easier than some of the intermediate ones. Could have been enlivened (and had more of a sense of "progress" if the background art changed over time, e.g. you are entering a more and more dilapidated section of dungeon or you are heading up towards the light. The last level should probably have something "special" about it (eg a treasure trove instead of a door, or a door that looks out onto the outside?).
Biggest complaint is that the door unlocking system didn't make it clear (unless I'm not noticing something - a colour or symbol key, or wires drawn from pad to door?) which pressure pad unlocks which door so you have to figure it out by trial and error. This is a pain in levels where route-planning is important,