Daggerhood is a pixel-art retro platformer where you are challenged to accomplish three things in all levels:
1) Getting to the exit quick
2) Reaching a fairy before she disappears
3) Getting 5 treasures scattered throughout the level
It is actually easier than it seems, since you don't need to accomplish everything in one go.
The game starts quite simple and gets more challenging on later levels. You friend is a dagger,
which can teleport you when thrown. You may also need it to kill the enemies.
Although the game has a lot of "worlds" and levels, you will only need to beat twelve levels to get all 1k gamerscore. This make this one of the quickest and easiest games on the site to complete. I did it in about 45 minutes, while also capturing a lot of videos and tweeting about it.
DISCLAIMER: I was given a code for the game in order to evaluate it.