I like the art style and I can see where you were going with what you were trying to achieve.
Obviously as many others have commented a tutorial or some better guidance on the objectives would have helped. Additionally as the dice rolls it gets hard to track which side is or isn't stamped in 2D space, it would have be good to have a visual tracker of some type in the UI to track what sides have been stamped and which face you were currently on.
Kudos for the effort though and getting it completed on time.