Arcade game for 800 MS points or less?

Spartacus Legends for free.


Fable 3 for free.

I think Castle Crashers might be 800.
Atomic Tank is a surprisingly entertaining arcade game.

If you want something a little off the beaten path I would give Outland a try.

It's sort of like a Metroid game mixed with the light/dark mechanic of Ikaruga. If you've never played Ikaruga, your character can alternate their alignment between light and dark at the touch of a button. When you are light, light enemies, traps etc, can't harm you. When you are dark, the same is true of dark attacks.

Give the demo for Outland a try if you are curious.

(Just trying to recommend something you may have not heard of.)