It is called "I want to be the guy," if you haven't already read the title of the topic.
I would show you a video of it being played, but most of the people who watched it called it boring and tedious when they didn't try it.
To download it, there are multiple copies. If you just feel like trying it out, download the demo. Or otherwise, download the one near the bottom. The others above are just mirrored versions of the game. Here it is:
http://kayin.pyoko.org/iwbtg/downloads.php
Good luck...
CONTROLS
Shift- Enter game/Jump
Z- Shoot
^, <, >- Movement
