The Gundemonium Collection is Now Available on Steam. Rockin’ Android releases the Gundemonium Collection on Steam with some new bells and whistles! The collection includes all three games: Gundemonium Recollection GundeadliGne Hitogata Happa These 3 games are considered to be among the best shooters in the doujin Bullet-Hell genre. Enjoy, everyone! A couple of us from RA might even poke around GundeadliGne netplay for a while today.