Black Survival is yet another BR-style manga, though it's confusing and isn't that great. Still, if you really want to read all BR-style manga, give it a try.
Btooom is another Battle Royale-style manga. It's much better than BR2, so if you need another 'play or die' fix in the vein of BR, you could give it a try.
Bloody Junkie is another self-proclaimed "Battle Royale-style" manga, and it too is fairly meh. If you really want more manga like this you could check it out.