No GBA carts to unlock monsters?
Monster Rancher Metropolis: Monster Rancher DS Archive (DS): Monster Rancher DS: Rumors, Myths & Hoaxes: No GBA carts to unlock monsters?
By jamesccg on Saturday, August 7, 2010 - 07:55 pm:

Is this true? Why did they not put that in?

By NoxStryx on Saturday, August 7, 2010 - 08:01 pm:

As far as i can tell it is true.
This is likely due to the current DS (The DSi)
lacking a slot-2, and them not wanting to alienate
those people.
I too lament this omission.

By Thorr on Saturday, August 7, 2010 - 08:41 pm:

This was a known omission. It is not available in this version. (it was available in MFDS1, but not MFDS2)

By Lisa Shock on Sunday, August 8, 2010 - 09:17 am:

This may have been something pushed on Tecmo by Nintendo, to keep up with the newer hardware.

But, Thorr is correct, MF:DS had GBA support. MF:DS2, which the North American game is a port of, did not have GBA support.