C-RUSH is a pretty generic shoot ‘em up, nothing too special about it, but it does have some pretty interesting viewpoint and position mechanics.
There are two mechanics that I found unique to the game, although they don’t really do so much in terms of gameplay. The first one is perspective changing. Your view of the map can be altered with a single key press. It doesn’t really help out much, unless if you’re trying to find out if your ship can fit through a certain space (which you can easily do with the default view).
The other mechanic is the rotation of your ship. There are two positions it can be in: horizontal and vertical. This rotation can not only help the ship fit through tight spaces on the map, but also allows more precise aiming. When vertical, your ship fires two shots, from the top and bottom of the “C” shape of the ship. When horizontal, these shots are combined and both directed along a single path. This is useful for taking down enemies that are a bit too thin for vertical shooting to work.
Other than that, the game is just your generic shooter. I can say that there are better shooters out there, even if C-RUSH isn’t necessarily a bad choice, it’s just a bit too generic.