Sorry for late reply. Currently the only way you can play Bleem games on GDEMU is the Bleem beta games. So Bleemed selfbooting games, Bleemshell or using disc swap loading the boot disc and pressing the disc change button on the ODE.
However, retail Bleem games still do not work. The creator of GDEMU is making an updated firmware that should release in the next month or 2, but this doesn't help the vast majority of GDEMU users who use the clones since we can't upgrade and flash our firmware without breaking the device.
If you want Bleem games on GDEMU, right now Bleemshell is your best bet. It changes D-pad to the analog stick, adds in the L2 and R2 and Select buttons to the D-pad, Left, Right and Up inputs respectively making WAY more games playable. It also adds nice box art to the games and lets you select the games from a nice list. viewtopic.php?f=30&t=12026