A nice addition would be a new type of block that would be triggered at each successful move.
So, after level 40, a new reset button would appear as someone would be able to dead lock the game.
To indicate that the block will be triggered, maybe have it have a special border.
I know very well the tool used and your work is really GOOD !
Level design is a bit fair but diversity of elements is GOOD too.
You may consider to ask the community to provide levels and implement them in your game.
As a reward, add their name in game (eg, their nickname in the bottom right corner).
You don't have to create a level editor or provide the CAPX, simply ask a drawing of it. Your elements are well designed and give enough cues to decode the scene.
This has a great potential. I bet that the author didn't want players to "back track". I beat the game if a couple of minutes (like 5) but I strong spatial skills and fond of maths and particularly geometry.
Maybe some sets should be designed ordered by number of backtracking steps required.
Special set with abstract dices could be interested.
Other sets with specials rules could be interesting too.
For example, you could have two kind of dices who share the same faces
(Let's say die [1,2,3,4,5,6] and die [4,5,6,7,8,9]) and a coloured dot in the middle of the square would tell which dice it is.
Lot of variants can be imagined :-)
But I think that it is not possible to create a puzzle as such that backtracking is not necessary but requires the user to use alternation.
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