Deadman Wonderland, Sword Art Online Recommendations
It has the same kind of style where you have to survive in order to get what you want and many characters aren't all the good guys
Alright you may be thinking that these are two entirely different anime series but please hear me out.
In both of these anime series the main characters get stuck in a place where they are forced to fight for their lives. Both of them can be considered games because in Deadman Wonderland participants are put up against each other in fights where if they lose they serve horrible penalties.
In both of the series the main character is trying to devise a way to get out of the place they are stuck in.
Wouldn't make it a top priority but if you ever run out
Both are survival genre in a castle/prison.
Both are about life and death games, though deadman wonderland didn't really have romance. they both have a rather mysterious girl (though shiro is alot more mysterious) and you come to understand the protoganist as the story progresses