First off, :game:'s graphics engine isn't really true 3D – while Descent put you in huge, sprawling tunnels that weaved in every which direction, with full six degrees of motion, :game: is much closer to the 2.5D map designs of Doom. In other words, the map designs are flat, with no rooms over rooms. In keeping with this, the controls are much simpler, as you cannot turn directly upwards or downwards, or even fly upside down. However, the engine does support slopes of various degrees, so there is some advantage over the old Doom engine.
Despite its fairly unique take on the FPS, :game: failed to make much of an impact. Nonetheless, despite lacking in interesting level design or character, it's a fun shooter from the rest, at least worthy enough for a quick shootbang diversion.