Quetra takes place completely in 4 dimensional space. It is not just a 4th dimensional mechanic added to a 3D game. Rather, it is a best effort modeling of what a 4 dimensional being would experience. Movement, collisions, weapons, everything is modeled using 4D math, even the explosion particles.
We launched a brief simple Kickstarter campaign to gauge interest, but the response was limited so we haven’t continued development. We may consider finishing it some day in the future if there is sufficient interest in such a game.