Download it here

Requirements: .NET 2.0 framework, DirectX 9c, and SlimDX (Sept 2011).
The download includes SlimDX, a code library used to interface .NET with DirectX.

New in this version:
New missile launcher part
New graphics for the Ship Builder interface
Blaster turrets in demo map
Various alterations to the collision detection engine
Basic support for custom shapes (as opposed to square-shaped sprites)
Other technical changes that won’t be mentioned here

A PDF containing basic instructions is included in the download.