I just got my 3DS XL last month and only have two games for it: Ace Attorney Miles Edgeworth and Nintendogs + Cats French Bulldog edition. I love these games and I need more, especially for playing on weekdays when I have maybe only 15-30 minutes to play. What are games that are still satisfying with these shorter play sessions?
Genres I like: RPGs, hack and slash (e.g. Dynasty Warriors), strategy, simulation, quirky casual games (e.g. Viva Pinata)
Genres I don't like: platformers, sports games, first person shooters
I need more diversity, because I pretty much just switch it up between Nintendogs on the 3DS and Warriors Orochi 3 on my Xbox.
(I know Nintendogs is barely a game, but I have a French Bulldog named Cao Cao. Therefore, win.) --- Now playing: Sleeping Dogs, Civilization: Revolution
Pushmo is a good downloadable puzzle game. The levels are fairly short. It's around $7 on the eshop IIRC. --- RIP City of Heroes and Paragon Studios - Killed by NCsoft. Not changing this line until Dimitri, Moosh, and Ricky appear in another LOZ game (7/20/09)
pushmo(pullblox)/crashmo(fallblox) are interesting puzzle games.
i quite enjoy the picross games, tough they may not be to everyone's liking. they are puzzles where you have to "piece together" a pixel-art drawing using numbers as hints, which requires a similar way of thinking as sudoku(actual gameplay is less boring though)
if you have a good memory the layton games can keep you busy for a very long time if you only play them in short bursts(it will remind you of the last couple of important events when you resume a save)
liberation maiden is an interesting shooter with only 5 levels, but quite a lot of "achievements" which reveal some background information about the world the game plays in when you achieve them.
while it's only a DSi-ware game, metal torrent is also a nice shooter. it's a bullet-hell type with 2 difficulties, and not many levels focusing on getting highscores instead.
potzol's/ketzal's puzzle is a game requiring quick tetris-like thinking as you guide a brick moving at high speed through holes in walls.
and pinball games like zen pinball and marvel pinball are always good for short plays, as long as you're not too good at it.