What Makes a Good Platformer?

Already a few weeks into my unnamed platformer, I've been thinking up ways to make it as fun as possible. In trying to think of the best qualities for platformers, I've thought of a few things, but I'd like your input.
So, what really makes an exceptional platformer? The story, characters, enemies, attitudes? Or maybe level design is most important? A variety of different blocks to break? Powerups? Replay value? Physics? And what about graphics, sound, even performance? What do you think?????!
And possibly the most important question, how can a good platformer not be a good Super Mario clone? Originality may be the most important quality, what's your opinion?
Wow, thats a lot of questions. Feel free to answer any, all, or none of them.
So, what really makes an exceptional platformer? The story, characters, enemies, attitudes? Or maybe level design is most important? A variety of different blocks to break? Powerups? Replay value? Physics? And what about graphics, sound, even performance? What do you think?????!
And possibly the most important question, how can a good platformer not be a good Super Mario clone? Originality may be the most important quality, what's your opinion?
Wow, thats a lot of questions. Feel free to answer any, all, or none of them.
Comments
... oh and yeah cute graphics, clever intriguing level design that you can rush through or spend time on exploring. Collectibles and beautiful parallax scrolling.
One thing that is important to me as a gamer is replay value, something which is echoed in this post, I like the opportunity as a gamer to collect multiple things in the level to achieve a certain goal, for example letters that spell out words (a bit like the old "skate" in tony Hawks) or a number of items to gain a reward.
The other thing i always liked was in the old mario on the gameboy (i think) where at the end of the level you had a chance at a slot machine of bonuses - jumping to hit the 3 blocks to see what you went into the next level with, 1 Life 3 lives, flower power that sort of thing.
Im sure there is 101 different variations to be discovered and I hope you find the one you need.