As a noob I managed to create for instance the X tile, wich dissapears when you step on it, and makes you fall in a pit, like a trap when you cross a bridge. The other is a one shot trampoline, that turns into a solid tile on the first contact with player, so that you'd have to pull off the jump on the first attempt or get stuck. You can easily create simple variations by tweaking the tile script but as soon as it implies modyfing the physics it triggers other problems and tou need more advanced knowledge. For instance dale gave us a modification of the physics engine to make monster projectiles shoot fast, it works great but in my case it makes the jumpthru platform unusable.. anyway good luckon finding a workaround for these tiles.