Contra: Hard Corps on the Genesis is considered to this day to be the most difficult game in the series, and since we're talking about Contra here, that's saying quite a lot. The original Japanese version was the first Contra game to incorporate an actual life bar, so you could take a couple of hits before falling over dead, but for some now-mysterious reason, that life bar was removed as part of the localization process.
Hard Corps: Uprising is an attempt to spin that game off into its own series, developed by Arc System Works, the Japanese developer that gave us Guilty Gear and Blaz Blue. The name works on a couple of different levels, because this is a game that's strictly for the hardest of hardcore players: a 2D sprite-based action game in 2011 that's difficult enough to drive 90% of its players into the nearest monastery. I've been playing these games for most of my life and I can't quite beat the first stage.
It's actually a shame, because Uprising is like some kind of beautiful dream I had when I was twelve or so. It's a beautiful game with a driving metal soundtrack and flawlessly hand-drawn sprites, and while it's difficult, it's approachably so. The action comes in a relatively predictable pattern, so victory is just a question of practice, memorization, and then flawless execution. The achievements even reflect this. This, like Mega Man 9, is distilled essence of 1980s gameplay, except nothing on the NES ever looked or sounded this awesome.
The biggest issue I have with Uprising is that it's got the weapon switching from Super Contra, which I always found awkward, and getting hit at all by anything costs you your current weapon. The default rifle is barely useful for anything and forces you to work a great deal harder than you already do, while getting the spread shot is, as is traditional in Contra, basically a cheat code. You can hold down the fire button and hose the screen down with a fan of ballistic death, which frees you up to dodge the return fire and jump over giant metal snakes. One hit, however, makes you drop the good gun and go back to the standard rifle, which means every gun in the game is almost too awesome for you to bother using it at all. You might as well not have a life bar, because getting hit once is enough to feel like a serious defeat.
There is a very specific kind of player for whom Hard Corps: Uprising is going to be better than crack. These are the people that keep Cave employed, who lined up for Gradius V, and who have characters from Metal Slug tattooed on their unmentionables. It's an arcade game for serious shooter fans, and only for serious shooter fans.