Thanks a lot for playing :) Glad you liked it!
I had put some extra effort for level design since the mechanics is not novel. So I am sure I haven't missed any code. For third level, you need to re-arrange the blocks using the extra platform piece. You can jump and block one piece and let the other cross the blocked one.
Also, for the jumping part, you can double jump.
Please do try again. If you are finding it difficult, I can maybe put a screen recording?
Thanks a lot for the feedback :)