Bangai-O Spirits
Nintendo DS
If you enjoy freakishly difficult games as you whittle away at your down time on your Nintendo DS, by all means, check out Bangai-O Spirits.

Insecticide
Nintendo DS
If you're left handed, or if you covet subtle humans niceties like, oh, eyesight, you might want to steer clear of Insecticide, even though it's otherwise a pretty good bang at that whole murder mystery action/adventure thing.

Geometry Wars: Galaxies
Nintendo DS
The success of Geometry Wars, that old school, 2D space shooter first making it's mark as an afterthought Xbox Live game, may have taken the world by storm, but it certainly didn't take long to the powers that be to bottle that tempest and then milk it for all it's worth. Not a bad idea, in this case.

Mystery Dungeon: Shiren the Wanderer
Nintendo DS
Don't let Mystery Dungeon's brightly-colored, superdeformed, non-threatening, Zelda-esque, top-down presentation (on your still-shiny DS) lull you into a false sense of security: This game is an old-school wolf in new-school sheep's clothing, and it is out to kick your ass. The only question is, do you deserve it?

Professor Layton and the Curious Village
Nintendo DS
You've played "brain games." You've lost yourself in the old-school, point & click adventures. Now you can do both in Professor Layton and the Curious Village for DS, a brain & click, er, click & brain puzzle adventure game from righteously respected developer, Level 5.

My Word Coach
Nintendo DS
Cheaper, more intuitive and just plain slightly better than its Wii-based sibling, the DS version of My Word Coach actually gives "edutianment" software a good name... for 15 minutes a day or so.

Advance Wars: Days of Ruin
Nintendo DS
Turn-based strategy games seem to particularly suit the little slab of portable gaming joy that is the Nintendo DS, and if there's one franchise that's damn-near synonymous with portable strategy, it's the Advance Wars series.

Phoenix Wright: Ace Attorney Trials and Tribulations
Nintendo DS
Even if you had a low LSAT score, you can still live out your fantasies of making witnesses sweat on the stand as you scream "objection" 'till you're blue in the face.