That's a good idea, athenian. Just don't hit 88 on the Pegasus Boots if you get struck by lightning (Great Scott, that'd be catastrophic)
A level in any game, eh...?
How about in Q*Bert, you have a level with trap doors, different gravitational pulls on blocks (In other words a sidewards block that would function as a normal block, just sideways), enemies that pushed and pulled Q*Bert around the board, explosives that Q*Bert could use to trap and destroy enemies (which also counts as a trade in for reverting the color of all blocks in a 1 block radius to the original color), and/or an apple seed that causes Q*Bert to double in size, allowing him to cover more ground for 3 seconds (believe me, that's a lot of time in Q*Bert)
Or maybe have a Sinistar (in the game of the same name) that has rotating shields that deflect the Sinibombs to home in on you. Maybe even some flaming meteors that destroy enemy ships, you, and count as 5 sinibombs on Sinistar himself.
How about a vertical level in Castlevania in which you climb up several staircases guarded by knights, and eventually moving platforms where you have to time your jumps (which are very stiff in that game) precisely to jump to the one above you. Bats, hunchbacks, or some Medusa heads would probably occupy that area. The weapons you get would be the time stopper, knives, cross, axes, that boomerang thingy, and holy water. The boss is the Kraken (aka GIANT SQUID RUNRUNRUNRUN) in a giant tank of water. In Castlevania, water kills you, so you can't whip him. You have to use knives, the boomerang thing, or the axes. His only weakpoint is his eye which he opens when charging or flailing, and closes when he shoot a fireball from his beak. His other attack is shooting out a tentacle to whip you.