Twitter has proven to be a nice source of gaming news today.
First I discovered (a few years late, admittedly) the Super Mario World hack known as Kaiso Mario World thanks to a tweet about Super Meat Boy. Then I was introduced to a cute, Flash-based shooter called Action Escape Kitty (screenshot below) thanks to a tweet from the folks behind shmups.system11.org.
I completely suck at this kind of game, so I didn't make it very far when I tried it earlier today, but don't let that keep you from giving it a go. (Pssst... you can play it here.)
See also: GunBlood, Robot Unicorn Attack, Treadmillasaurus Rex and Winterbells