Over by the construction girl, on the left against the wall there is a cave entrance hidden behind a tree. Go into that cave, you will come out up top where there is a small box for you to push down to get to those boxes.
The top right corner. Go up the ramp on the top, and jump those two corner blocks and then around the corner. That's how you get the key. The small boxes you move around are only to get the coins.
So I looked at the steam page of planet lust, developer has a different username by the way. It looks like it is done and it is coming out April 16th. So I'm assuming the next update Will be mid to late April.
