/jp/ - Otaku Culture

So I decided that before I open portal I want to try playing this game he plays, because he is cool but I have complete no idea what game is it, and I it looks cool (I did read this manga where he goes and massacres half of Gensokyo) and this would be awesome to know that game name. Could you help me /jp/? Also do you think it's worth trying even if it Will be delay to opening of portal? (probably few months but I hope no). Also I think if I play this game I might become even better legendary person (I already was once but now I need better legend).