Original but still based on the anime/Manga obviously.  Tho the game has nothing to do with it besides some references and themes. 

It's a 2d platformer shooter. Where you play as a cop hunting down giant titan bugs and the source of these bugs, our antagonist Aryn.

Offers a nice story and a * secret ending *

You can play it here : https://joshuajrodrigues.itch.io/hunting-aryn-yayger