well if your xbox is modded then you can have all the shooters under the sun,via mame and fbaxxx.
xbox shooters list.
shikigami no shiro 2http://uk.youtube.com/watch?v=nYnU4CAmfnE
there was another shikigami no shiro and i think that was a special addition.
thats about it really when it comes to disc based releases and of course there was some xbla stuff for xbox1.
but if you have a modded xbox then with mame and fbaxxx,there are tonnes and also with pcsxbox you can play all those ps1 shooters like raiden2,raiden dx,gradius gaiden,rtype final,einhander,terra driver.......................and so on blah blah!