Gundam X probably isn't in this because... well, can you imagine how nightmarish it would be to try and turn the Satellite Cannon into a functional in-game weapon in a 3D action game? Even RPG series like G Gen and Super Robot Wars tend to implement it poorly, making it either too powerful or uselessly weak.
Major units to appear in that PV just linked:
- Aquarion from Sousei no Aquarion
- The lead unit from Orguss, the second show in the Super Dimensional Trilogy that Macross launched. The Orguss units are very similar to the original Macross units, so they may be the "Robotech" ones you saw.
- Destiny Gundam from Gundam SEED Destiny
- Valkyries from Macross Frontier. Since Macross was part of Robotech, you may have recognized them that way.
- King Gainer from Overman King Gainer
- I forget the name of these guys, but yes, the knife-in-mouth dudes are from Full Metal Panic.
- The caped Gundam is, I think, Crossbone X2.
- The unit fighting in the tunnel after that is one of the Lancelot versions from Code Geass R2. I disliked R2 on the whole so I couldn't say which, sorry.
nu Gundam is in the game (check out the longer PV I posted), but probably not in the promo video because it's hard to get worked up about CCA units anymore. CCA has been in every ACE game, almost every SRT, and I think every G Gen game. You can play nu Gundam in basically any of these types of games you want, really.
I didn't know Acid Black Cherry was the Janne da Arc's dude side-project. Thanks for the info, I'm going to add a lot of ABC to my music library now. I love Janne da Arc and when I heard this song I was like, "Hey, I dunno this band but man, they sound a lot like Janne da Arc...."