Super addicting gameplay! It took me a little while to figure out that the gray bricks already on the lighthouse were platforms. I kept trying to place initial blocks with left click and it only worked occasionally, but I eventually realized that I only got blocks to place after climbing a certain amount (or waiting a while).
I really like the 2.5D wrapped aesthetic. I wonder if it would be possible to make the blocks slightly 3D (i.e. have them protrude slightly) so you can see them more clearly as they come around the bend of the lighthouse and more easily distinguish between what can be jumped on (e.g. plants) and what can’t (e.g. windows), but maybe that would detract from the aesthetic you have.
Super jaunty music too!