Flip and Go
It's a common enough problem for a cute little alien: you promised to meet your sweetie in the park, but there's candy. So why not collect the candies and bring them to her? In Flip and Go, a game from Lampogolovii, making the date perfect is not as simple as it looks.
As with most puzzle platformers, use the [arrows] or [WASD] to move. You can use [Z], [X], or [C] to pause everything for a second and flip your environment. Your shadow helps you figure out where you'll end up after the flip, though there's a wide enough variety of challenges that sometimes it's deceptive. Dark blocks don't flip, for instance, and neither do you, but the girlfriend does when you get to control her. Add pulleys and locked doors and a host of other elements, and you have quite a mindbending diversion. There aren't a lot of levels, but what Flip and Go lacks in length, it gains back in originality, challenge, and sheer adorableness.