Lots of people have submitted games where you travel from the third dimension into a 2D world but the opposite is rare!
The inclusion of achievements (or an achievement) was an unexpected bonus!
Poor Leo, after his sad mushroom picking I went back into the 3D world and jumped very high... and then I went off the edge of the world and fell forever. He was excited to discover 'Up' but probably didn't enjoy 'Down' quite as much.
It doesn't show in the screenshots, but for me playing in the browser there were noticeable gaps between the tiles so everthying appeared to have green gridlines.
