The game is still under development. Video shows the basic concept of the game, looks like you can change parts during battles by the loots you get from the battle field and enemies.
-BANDAI NAMCO ENTERTAINMENT EUROPE
"Watch the very first gameplay from New Gundam Breaker! Build your own Gunpla Mobile Suit Armor and team up with your up to 2 friends to take down other Gunpla enemies and huge bosses. Don’t forget to strip them of their best parts! ;)"