Lost Heroes (ロストヒーローズ) is probably an RPG game that could appeal to a wide population of otaku because it features the awesome combination of Gundam, Ultraman and Kamen Rider, and they are all in SD (Super Deformed) style!!
According to Andriasang, the game is supposedly a revival of the classic Compatible Hero/Konpachi Hero series. Even though the gameplay graphics looks kinda dated, its still rather cool because how often do you see three classic otaku elements being featured in the same game. Then I was thinking that if the developers had replaced Gundam with Super Sentai heroes, then it would become an awesome trio of tokusatsu heroes game.