Rumble's Revenge is a tie-in web game to a children's television program which isn't exactly the most auspicious game premise. Luckily the game, and the show it's based on, Gravity Falls, are both wonderful. Rumble's Revenge is a quasi-sequel to an episode of the show where a fighting game character invades the real world of the characters; this time he's sucked the characters into his own world resulting in a Gravity Falls take on Final Fight. While the game is filled with references to the show it's still a fun way to waste some time, even if you've never watched an episode.
The Sucker is a zombie game where you're the zombie and you're feeding on everybody else. Of course to make the game simpler you're a running/leaping/super-strong zombie rather than the shuffling Romero type, but the game lets you have so much fun with your rampant destruction that I'll allow the deviation from zombie canon.