Today we highlighted Sentinel 3: Homeworld in our Price Drops section, which lends some credence to this latest news. Now we know why you can get it for free - a new Sentinel game is on the way! Funny how these things work.

As we mentioned earlier, Sentinel 3 was one of the best tower defense games to come out in 2010 and it's stood up since then. But games in the iOS world come fast and furious, so it's time to look ahead at what Sentinel 4: Dark Star will bring to the table.

According to a blog post over at the Origin8 web site, the game world is going to get much bigger indeed. But they aren't planning on fiddling with the secret sauce either, as "the classic core Sentinel gameplay is intact." Which is a good thing. You don't want to mess with anything that's garnered your game a Metacritic score of close to 90.

But that won't stop Origin8 from putting in lots of new story and content elements into the new game. They promise that fans of the series can expect bigger maps, a new alien race with exotic technology, different weapons, and story that will take iOS gamers along for a great ride.

There's no specific release date yet, but they are targeting an early 2013 launch on iOS.