Cool wee game. I was surprised when the timeframe changed and I needed to ground myself in all of the new visuals. Nice mechanic!
I think having a phased approach to collecting with awards along the way is need to make the game more engaging. E.g. at 100 coins, reward the player with a bunch or keys that appear or even a new skill/behaviour. At 250 coins, just give them an award or achievement (doesn't need to modify the game tbh - just modify the game space in the player's head.)
Great work on building out all the maps and levels too! I need to do some good wee puzzley exploration.
Well done!