This level is not actually all that difficult. It's actually quite easy. The only thing that makes it difficult here is that there's no single-move undo. If you've made a mistake, like push a box into a non-goal corner, the only way to recover is to start over by refreshing the page.
#####;
# #;
#### # # # ####;
# ##### $ ##### #;
# *+* #;
# ############# #;
## ##;
# ############# #;
# # # #;
##### #####;