I reviewed this game back in August 2009 when the game came out. I gave it a very poor score because of the big lack of contend - only one level! But, appently, the plan was all along to add extra contend for free later on. They just had to release "a beta-version" early on because they ran out of money (note: their own money!). The new contend pack released back in January helped the game a lot. A campaign with five maps was added, and the chance to customize your character and purchase weapons. I still think that 6,99€ is a bit too much - 4,99€ would be a better price. Anyway, the developers are still working on some multiplayer, which will probably help too.
Back on topic, I once again have 100% on this small game. The new achievements took about 3 extra hours to complete, where the last two hours was basic kill grinding.