Even really similar games within the same genre have different styles of difficulty.
Past a certain skill level, basically every DDR player can pass basically every song, but the game is still hard because the timing windows are pretty narrow, so the goal is to get a high score.
I
n Pump it Up, which is basically the exact same thing, the timing windows are super wide. If you have a pulse, hitting an arrow means getting a Perfect. To compensate, the songs are super-fast and require weird turns and stufff. The difficulty is in passing the songs, but once you're good enough to reliably pass, pretty much everyone gets about the same score.
And then there are games that thrive on what would be considered fake difficulty in another context. Super Meat Boy, God Hand, bullet hell games, etc. If I'm playing Mario, and all of a sudden there's a need for me to jump with perfect timing and perfect aim, I'm gonna consider it a cheap shot. In I Wanna be the Guy, though? Hell yeah :D
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senorhousemouse