Thank you, and apologies for the late response. I thought of making an important-looking door to the level that takes you to the end, and a special sound when it opens, I just never got around to it. What I most wish I could have done was design a few more puzzles that were actually challenging, as most of the levels in this exist just to teach the player how the mechanics work. Whenever this becomes a full game, I plan on it having something around a hundred to a couple hundred puzzles.

You're right, I definitely regret not making it faster. It's actually faster to play by tapping the direction keys instead of holding them, which is how I'm used to playing sokoban games, and I guess that's why I never felt an urge to change it, unfortunately. I'll keep that in mind for later post-jam versions of the game.