I really love this anime. It saddens me that some people say it sucks, I mean yeah the anime didn't explain much of what the game does but if you actually go to forums and tumblr, etc you're bound to find why the characters act the way they do.
I've literally been in DiaHell for the longest time and not because the characters are attractive (that's a bonus) but because of how cute and sweet they would be if they showed actual development in the anime. Now I have not played the game but I've read a lot of their back stories and I can't help but feel sorry for them and cry. ;u;