Sugar Cube is a kawaii-cute platformer -- responsive and well-tuned, with one unique mechanic that makes it interesting.
At various points on the level are hidden items -- often platforms -- that are revealed, and switch "on," only when you pass through or near them. As you move about, the four squares immediately around you are tinted, and show the hidden items. Frequently, there are small "lights" on the screen that show the hidden items, in ghosted form, until turned on; but often, items are revealed only when you activate them. Finally, by holding "shift" while jumping, you can prevent items from "flipping" from active to inactive state.
The result is that each level holds surprises, and you have to learn how to time and use activations to get to the level end (represented by a door); sometimes you want an item to flip to inactive state to get through its location, while often you want to turn it on, to provide a location or item you can use.
It can be a frustrating game at times; finding the path often involves a fair bit of trial and error, with multiple deaths; luckily the levels are short, so restarting one is not a pain.
Platformers can be a sameness after a time; Sugar Cube has enough novelty to refresh the essential gameplay.
Sugar Cube was named Best Game at the 2010 IGF China awards; the current version is a much-expanded version of that game.