Oninaki is disappointing. Mostly because the right elements were in place to make it great and it's so thoroughly mediocre. Tokyo RPG Factory have yet to release a truly essential game. As it stands they've released three games with interesting ideas and spotty execution. Perhaps one day they will get it right and release a defining RPG. However, today is not that day, and Oninaki is not that game.
Overall, the game offers a great experience that even though I got tired of after a few hours, I came back to multiple times. The game modes give a solid bit of excitement, but the real fun to me came from the online experience and special vehicles you can use to cause real destruction. I would give the game an overall 4 out of 5. I give it this based on its overall gameplay falling a little short in variety to me, but keep in mind that leaves plenty of room for them to eventually improve on the game.