Make your way to point A, and wait until the monk to your right is at approximately point C. Then move down 2 or 3 tiles, and the monk should drop through a trapdoor and out of play.
The yellow door is not accessible, so just ignore it. Don't bother to get the yellow key, either.
Light a bomb at B, then follow the red line. Go to point D and light a bomb there. Make sure you are standing on the right half of tile D when you light the bomb, or you may not be able to get far enough away to avoid the blast. (Yes, you can get far enough away from the bomb, even though you're standing in goo.) Then exit to the left.