I'm sure it's something you noticed, but I have to mention it because it disturbs me, lol: The jagged pixel edges on the sprites with non-right angles. The square looks perfect even when it rotates, this is out of place with the constant presence of the pixel edges of the triangle. It's like you're scaling the game up but letting it add the pixels. I would suggest either scaling it 1:1 (so square rotates with jaggies) or using primitives (preferable, everything is perfect). :)
Yes, I know. :)
When I created the shapes I had planned to align the outline with the chessboard pattern that is created when shapes merge. But then I changed the spacing of the chessboard, so that this makes no longer sense.
I will convert the shapes to vector graphics ... but maybe not for the first release.