Just because a game is hard doesn't mean it is bad. However, harder games are notorious amongst gamers for being punishing to beat. This is a list of games which are in my opinion the hardest games in history.
5. The Cleaner:
http://gamemakergames.com/?a=view&id=4733I am surprised to see how hard this game is. Like all darthlupi games, this one is both fun ad challenging in a special way. But one you get to that monster cat thing, you will see what I mean.4. Mushihime-sama
http://www.youtube.com/watch?v=nscP9QpXoFMWhat the hell? The screen is covered with bulltets? I am blind. This game has received the award from Gamespy for being the toughest game in history. Why? Play it on Ultra mode.3. Ghosts N Goblins 
http://www.newgrounds.com/portal/view/175060This game is hard ad hell. Even the guy playing the demo dies. The problem is that, unlike Mario, Sir Arthur, the hero of Ghouls, never learned how to control his momentum in the air. That means you're committed to your jump once your feet leave the ground. If you happen to land on a pile of zombies, so be it. Checkpoints are few and far between, too, so you can plan on playing through each of the game's levels over and over again until, by some miracle, you happen to make it the boss - only to be killed and have to do it all again.2. BattleToads
Battletoads took the side-scrolling beat-em-up nature of Double Dragon, but added a whole lot of variety in the level design. One area will find you repelling down a bottomless pit, while another will have you racing around on motorbikes. This variety actually augmented the difficulty of the game, as it required practice, skill, memorization, and lightning-fast reflexes to avoid the numerous obstacles and instant-kill traps scattered throughout the game. To this day, Battletoads is not-so-fondly remembered as being nearly impossible to beat. It was so hard I had to play it on an emulator, at 1/10th the speed, with gamegenie. It is that hard.1. Punishment
http://gamemakergames.com/?a=view&id=3741I could never do it. Why? Oh why? I could never beat this game. It was just, …. punishment. If you can beat this in one siting please do. Messhof is just a wonderful bastard form making this game.
I have. That games awesome. I'd like to see someone post a speed run of Punishment. That games a bitch.
You forgot Vanish. Look at my games if you're curious.
Silly Kairos,using punctuation too much
http://www.youtube.com/watch?v=PP-mePr1-ZQIs that battletoads?
Yea yea Serprex, you barely use them :P
No Shork, it just has the title Battletoads
BattleFrogs
The cleaner is pretty easy if, once you reach the tunnels with red dragons, you just kill them over and over again. Then you get Bender's Balls all the way leveled up and the rest of the game is a piece of cake.