Cool game! I don't undrestand why no one still wrote anything. Maybe browser version could help more with collecting more feedback as it would require less steps from the player to try the game.
I left a comment on the game itself. I only got to level 5, but still can say that it feels pretty good and challenging. I was confused a little at level 4 because there's realy no need to set the reverse block. Maybe removing a wall and forcing a player to set the reverse block could help. I ended up completing level without reverse block for this reason