The M2 Shot Trigger stuff is all incredible but of course, expensive. Aside from Battle Garegga there's also Ketsui, ESP Ra De, Dangun Feveron, and Mahou Daisakusen (Sorcer Striker). The latter is the first in a trilogy of shooters which also includes Kingdom Grand Prix (which received a superb Saturn port) and Dimahoo.

I believe M2 have the right so the entire Toaplan back catalogue now, so expect the likes of Tatsujin 2, Batsugun and other wonders in due course.