Thanks for taking the time to give your in-depth opinion, there's a lot of useful feedback here!
I agree that the controls need more fine tuning and the graphics could use a good dose of unifying paint, I had to stop somewhere to make progress on the actual game mechanics and progression, but I wasn't fully satisfied either. For the time loop, I also agree with you there, it was an afterthought to fit one of the themes, but I won't keep it if I create a new and improved version.
About making the battles random, I could have done that but I think it would have made the game more tedious, honestly. I placed the encounters so that some are mandatory but you don't have to fight all the time to get from point A to point B, I think the pacing of the game is better for it.
Yes, there is a levelling up mechanic, that's how you unlocked that healing skill for the cleric. The level of each character is displayed at the bottom right of their portrait in both battle and exploration, when you level up there is a popup that appears on the portrait, and there are lots of tooltips. You probably never saw them if you played only using the keyboard, but you can hover most UI elements with the cursor and a brief explanation of what it is will be displayed. To be fair, I'd say there are lots of signs on the UI that the characters can gain levels.
About escape quitting the game, you don't actually lose any progression if you accidentally hit. The game is saved automatically after each battle and each time you collect a shard. I take player time very seriously and wouldn't dare taking their entire progress away 😉