Space Impact: Kappa Base was released in February during N-Gage beta testing, then it vanished after the full launch. It's now back in the Showroom's "Available Games" section. If you can't see the game, click on the headline of this news item to find out how to make it appear. In case you want to know more about the game, here's AAN's review of SI:KB. (Thanks to Steve on AAS for pointing this out!)

How to get Space Impact Kappa Base to appear in your showroom:

Our N-Gage phone's showroom's "Available Games" section would not show us the Space Impact: Kappa Base icon. Restarting the app and restarting the phone made no difference, the game just wasn't there.

UPDATE: Apparently there's an even easier method to get the game to appear: Go to the showroom but do NOT go in the "Available Games" section straight away. Instead, click on Options menu, then Update Now, then go to "Available Games". This option really ought to be available on on the "Available Games" page as well, indeed it ought to be an automatic update really, but for some reason it isn't.