Seems to me they're using EX Troopers' engine.
Who the hell owns Kaijuu Busters anyway? That's one game I'd like to see on the 3DS, and localized to boot. It's basically Monster Hunter in Ultraman universe. I've played some on the DS, and while the graphics aren't anything to be amazed by, it's still a pretty good game, because I get to kill kaijuus and wield equipment made from their materials.