Just a completely random thought I had: what if you had an action
RPG (i.e. Diablo sort of thing) in which your power scaled *down*
over time, so the game got more and more challenging as you got
better at it?
There would have to be some sort of reward tradeoff here; something
like better loot or better score or better acheivements or
something. Just think it might be a neat idea to play with.
Perhaps better XP or similar, but the more powerful your skills
become the weaker your body becomes, or vice versa? Or you need to
harness your chi or whatever to be able to hit high-level monsters
at all, but the more in tune with your chi you are the more in
their world you are, so all monsters get bonuses against you.
What lead to this idea is noticing that RTS and FPS games will
typically start you off with simple scenarios and build up to more
complex, difficult stuff, whereas ARPGs give you more and more
powers over time, so that the first few levels are often the
hardest, which seems a bad plan. Some of that is just "lol you
fail at game balance", I suppose.