Tag DS?
I was just testing download play with one friend using R4.
Fifa -06 is really fun
Mario Kart -very fun
Bomberman-very fun
Madden 08-very fun
Club House games
Konami Arcade Hits
Metroid Prime Hunters
Nervous Brickdown
Tetris DS
Point Blank
Ridge Racer
Brain Age
Oh the R4 does have 100% download play support now after my testing. These games all work perfectly.
P.S: These roms are all trimmed by NDSTokyotrim, so I can confirm that the trimmer does keep download play in tact.