Sony have announced Rampart, a new budget download-only title coming for the PlayStation Network (which I assume means only for the PlayStation 3, though platform specifics are not mentioned in the press release:

A Unique Strategic Warfare Experience - Brains and brawn will beat them all as players combine rapid cannon firing along with careful castle reconstruction on the road to victory.
Up to Six Levels To Conquer - Challenge the computer in up to six levels and combat against three versions of enemy ships.
Multiplayer Action - Challenge up to three other players online. Players can destroy their walls in addition to tracking individual scores on the leader boards.

The introductory offer price is 3 Euro (think AU$6) and it should be available now.

Wow that's awesome. Rampart is s***-hot!

is this it???

http://www.gametrailers.com/gamepage.php?id=4771