Here's another oldish release of a Gundam arcade game: Kidou Senshi Gundam Seed: Rengou vs Zaft. The game uses the same system as GvG, mostly because GvG's was based off of this, so it's easy to move around and string combos.
The only hard part is that there's a slightly longer cooldown between each move. This game also features a story mode, to which you can follow either the Earth Federation, or Zaft, and rip shit up while upgrading your mobile suits from shit to Jesus Yamato's Freedom.
'tis a shame that the GSeed Destiny one never ported over to the PSP... I enjoy shutting up Shin with the Strike Freedom.
Gameplay video of a 2v2 match:
Find it here