Isn't that I Wanna Be the Guy?
I don't count artificially hard games as hard games. IWBTG was only hard because the developers made it so things would literally pop out of nowhere with no implication of their presence and only gave you one hit til death.
I think that was a part of its appeal. Once that wears off, it's pretty mediocre. The boss battles are nice though, IMO.
a number of years ago, there was a japanese flash game with ascii graphics using a bunch of 2ch memes… along the same lines as iwbtg
and there's always the various asshole mario hacks
Do you mean this?http://www.geocities.jp/z_gundam_tanosii/home/applet/Main.html
There's also this game, which is kinda long the same lines, and parodying megaman:http://king-soukutu.xsrv.jp/flash/owata.html
The creator of that second game also made a game called "Rocco Chan", which is a pretty good Classic Megaman clone, and decently challenging.http://king-soukutu.xsrv.jp/flash/rokko.html
yes, the second one! I'd forgotten the name