Fun game! I like the idea of having to cheat to get the gold. I didn't figure out the last puzzle, I assumed I needed to get the magnet there but didn't think to use the cards to build a bridge (I watched the trailer after playing). I do think that the collision stuff is a big obstacle for players. If you wanted to keep the rolling you could have still had the player "pick up" the items but visual they still roll around, just locked in front of the player.
Overall it was really fun! Please check out and rate my game if you have time