Just bought that on Wii Shop Channel yesterday. Would have bought GBA version, but shipping changes the price from a few dollars to +$10. I used to be able to pull parts of the wall out as mushroom blocks on one of the levels, I think it had tree textures. I just had to tap B at the right time. I could even put the mushroom blocks in the gap to use as a platform. I'm pretty sure I found out the put holes in chains glitch on my own as well.