Now it's going waaay off-topic
the Amiga doens't have too many shmups. And vertical shmups (my fav) are even more rare.
And the best thing for shmups isn't MAME, but RAINE. Raine is THE SHMUP emulator
be sure to get it... and play all those great Cave/Taito/Toaplan/Raizing/Psikyo shmups