look. dont do invisible blocks. I use those to make it annoying. if you want it to be hard, make traps like with bullet bills and other stuff like in snowy challenge. if you want to make it easier, umm, im afraid i cant help you there.
I have to agree with livio here. when i hit the the second invisible block, i stopped trying. looked at the rest of the level - it looks way too hard, once more. remember guys, we're still newbs to this game. this looked alittle random, as there was nothing special here.