Natively the n900 doesn't have any really decent games besides Angry birds, all other games are half bothered releases that were a cute side project till the dev got bored and moved on, but thats just the Linux way.

That then leaves emulation, but heck. Even our emulator ports are "Yes! It compiled, that'll do."

Try Muppen64, at around 950 Mhz Banjo Kazooie, Fzero and Mario run decent enough with sound but will kill the battery in about 5 hours.

Then there are the Genesis, SNES, GBA and SCUMMVM emulators. They are ported to anything thats had a processor so nothing special there but they are fun. Torrent sites are your friends on getting quality games packs.