I'm pretty awesome at games (if not very stubborn too in practice), so normally I can get past every game with enough time at it. I mean, I've beaten games like the NES "Castlevania" series, "Ninja Gaiden 1 (NES)"; heck, even "I Wanna Be The Guy". More often, I'm not the GREATEST gamer, since I can get my *ss handed to me whenever I go online (especially at any FPS game [which I SOMETIMES play, cause I'm just not a huge fan of the genre at all]), but when it comes to most anything else (or to my friends), I can beat them down pretty badly.
However, there was one game I never beat 100% and another I failed at so hardcore because the game WAS BROKEN (I swear, I've seen people do it, but they only got lucky in comparison to me -_-').
1) F-Zero GX (Gamecube)
I've beaten the game and I'm VERY good at it, but ANYONE WILL TELL YOU that this is one of the HARDEST GC games EVER MADE (When it comes to unlocking all the content). There's so much to unlock and, from what really matters being the new characters, to get them, you gotta beat story on the highest difficulty. That's INSANE to do. There's even one level where you got a speed-sensitive bomb on your ship and you gotta run through a course that takes about five minutes to complete (basically) without touching a SINGLE THING. I've NEARLY made it (last stretch), but never done it yet. Probably could, but that's not even the hardest level. There's another 3-4 that are harder (Like the ghost race on the track with NO WALLS).
TO add salt on the wound, this game's save file is so well protected, you can't move/copy the game save AT ALL. So, if you wanna hack it, you gotta get the AR hardware to do is (Cause my Wii's software modifications certainly can't do the trick alone now). Such a fun and awesome game, but SO... d*mn... hard. -_-'
2) Megaman: Battle Network 1 (GC) [Or whatever it was called]
I rented this from the video store once. It was my first Megaman game and... WOW... did it suck. I mean, it had nice graphics (for the time) and worked SORT OF well, but the game was broken with how you fought the bosses. First of all, most Megaman games require memorization of patterns, or certain weapon uses, or being plain GOOD to beat them normally, right? NOT WITH THIS GAME! The first boss was Fireman and... WTF, you gotta know the ONLY WAY to avoid his fire move (since it's a huge, long, flame that last for a couple of seconds) it so slide away from it and into a wall (cause ducking doesn't work). That's so narrow an escape window it's almost cheating to beat the boss, and it's the ONLY way to dodge the move... and this is the FIRST BOSS... WTF?
However, I beat that boss. Next boss was Gutsman and... Never beat him. You wanna know why? Well, he walks around slowly and you're supposed to avoid him and just shoot the cr*p out of him to make him die. Therefore, he has a TON of HP. Why didn't I beat him? Well, unlike most enemies, your normal blaster doesn't hurt him, so you gotta use your limited arsenal of chip-powers to beat him... NOTICE I SAID "LIMITED"! I expended EVERY SINGLE CHIP I HAD AND HE WOULD ONLY COME BARELY CLOSE TO DYING... WTH MAN! I've watched videos and, the only reason they beat Gutsman, was because they had more chip-powers than I did. WHAT A FATAL FLAW. That game wasn't even that hard in comparison to other Megaman titles (beaten 2, which really isn't that hard at all, but harder than this game), but all I could see was how BROKEN this game was in its design. Much like other bad titles, don't make it so cryptic to dodge/beat bosses in your game and (much like "Zelda: A Link to the Past"), don't make a boss that REQUIRES LIMITED AMMO TO DEFEAT, cause what happens when you're out? The game's OVER.
Beyond those games, I normally suck at puzzle games, but I can still play them just fine, so... Yeah. I can even stand my own within legendary hard games and never suck at most any genre in general, but when a game is either designly flawed or broken, it more pisses me off to even touch the title, let along play it. After all, I make games and I know how to do them right. When I see professional BS... I rage (especially when I can't beat it because of it).
THAT'S LORD GAVIN TO YOU!