just tried the "making the cloud man disappear" thing on the American version. It does indeed work. I don't know how, it just does. Guy vanishes when you hold a block under the floating diagonal blocks.
Dunno if it's fair to call this a speedrun, considering that the player dawdles to kill time in every level. That said, i imagine the people who like speedruns are also the sorts of people who like this sort of thing.