This game is great and very unique. I cant solve tha last puzzle :(
Probably multiple solutions, but this is what I did:
Roll right (gaining -4), up, and left. Keep rolling onto the + tile until you have only -1 left. Then go up (over the multiplication, making your total -3). Roll your die in a square in the space to the left of the + - sequence until 5 is facing up. Rolling to the right should land you with the correct sum (-3 + 6 - 2 = 1).