One of the best Gundam games I've played with a nice mix of characters/mobile suits from numerous Gundam universes.
I'm a big fan of the Mobile Suit Gundam 0079 series(it's one of my favorite anime series of all-time)and I enjoyed the Gundam Wing series somewhat(although I wouldn't call myself a big fan of the Gundam Wing series)and I've watched all the episodes of Gundam 0080 and some of the Gundam SEED and Victory Gundam series.
This game takes characters and mobile suits from the series I've mentioned above(with the exception of Gundam 0080)as well as characters/mobile suits from Zeta Gundam and other Gundam series and puts them into one story.It might sound like a silly idea at first but it lets you create new friendships between characters from totally different universes and it allows characters/mobile suits from different universe to battle eachother.
Dynasty Warriors Gundam 3 is the first Dyansty Warriors Gundam game I've played so I can't compare it to the other DWG games but I've played Dynasty Warriors 5,6,7 and I can tell people who've played a DW game before they can expect the same sort of hack n slash gameplay but the mobile suits have features such as thrusters(which allows them to travel fast through the air and some mobile suits can even fly for periods of time and the thrusters are useful if you want to distance yourself from enemies or when you want to get to an ally quickly)and all mobile suits can shoot projectile weapons.
Just like in the DW games,in DWG3 you can capture enemy camps to stop enemy reinforcements from that area and so you can have reinforcements arriving in that area to help you.You'll also encounter enemy officers which are stronger enemy mobile suits which are often piloted by characters from various Gundam series and these officer's mobile suits can withstand a lot of damage.
The environments in DWG3 are small but it purposely crams you into small areas with lots and I mean LOTS of enemy units(enemy mobile suits,tanks etc.)and it makes the action more constant and intense.Besides just hacking and slashing and shooting every enemy,you'll need to aid your allies in battle if you play the game on the harder difficultie and if they're forced to withdraw it can make winning a mission much harder.
Sometimes you'll need to defeat some enormous robots which look much bigger than your mobile suit(even though your mobile suit is already huge and dwarfs trees and buildings already)and fighting against some of these enormous robots can be epic because they can lift your mobile suit up with one hand and throw your mobile suit as if it's a toy or will try to stomp on your mobile suit or shoot powerful weapons at it which means you'll need to make use of the thrusters and be able to dodge the beams from the powerful weapons.
Sometimes the gameplay can feel frantic and epic because there is times not only will you be surrounded by many enemy mobile suits,you'll also be facing against enemy officers and the giant robot things at the same time.
What kept me interested in this game is the characters such as Amuro Ray,Char,Kai,Ramba Ral,Heero,Relena etc. and seeing them make alliances with or battle against pilots from different universes and I like being able to use the original Gundam from 0079 and have it fight against later Gundam models from other Gundam series/different universes.I guess you'll need to be a Gundam fan to appreciate this kind of thing.
The controls work well and feel very smooth and fluid and it's easy to pull off combos and I love using a combo before/after I dash towards an enemy using the thruster.You can perform some sort of super attack which requires SP and you can use up some of your SP to perform a partner strike(which is your partner will attack enemies on the screen and this can be useful if your SP isn't enough to do that super attack).
Besides the story based missions(chapter missions),there's friendship missions which allows you to create friendships with other pilots and it gives you new selectable partners.There's history missions which allow you to replay events from a particular series,for example if you're a fan of Mobile Suit Gundam 0079 you can do missions that relate to certain parts of the Mobile Suit Gundam 0079 series.There's also memorial missions which allow you to earn new skills and there's collection missions which allows you to earn new designs for your suit.
If you equip new skills it can include making your combo attacks longer which makes a big difference in battle.Your pilot's skills can level up and you can level grind if you want.
The in-game graphics and cutscenes have a nice style that looks like it's influenced from a cel-shaded style and comic style.It looks cool when you see the mobile suits dwarf buildings,trees etc.
The music has influences from electronic/J-Pop style but which sounds fitting for the theme of the game but it would have been nice to have theme music from the different Gundam series.
Overall I found this game to be an enjoyable title and if you're a Gundam fan you can say it's an excellent title and it's easily one of the better Gundam games to have been made.