No Halo game has ever been available on Steam, but that's going to change. Microsoft announced today that twin-stick shooter Halo: Spartan Assault will launch through Steam on April 4 for $5. The game originally debuted on Windows Phone 8 and Windows 8 last summer.

Halo: Spartan Assault later launched for Xbox 360 and Xbox One.

Microsoft also announced today that from April 3-9, you'll be able to download Halo: Spartan Assault for Windows 8 and Windows Phone 8 for $2. The game will see a permanent price drop to $5 on all Microsoft platforms starting April 10.

Halo: Spartan Assault includes 30 missions where you'll battle against the Covenant in a story set between the events of Halo 3 and Halo 4. The game supports Steam achievements and leaderboards, and you can use either keyboard/mouse controls or you can plug in a USB Xbox controller if you want.

We have reached out to Microsoft to ask if the release of Halo: Spartan Assault means gamers can expect more Halo games to come to Steam. We'll update this story with anything we hear back.