Seriusly the best tower defense game I've ever played. Only things missing would be the obvious fast forward button, more upgrades and upgrade types, and of course, MORE LEVELS! I understand you can only do so much, but it is true that a level-fest like Gemcraft: Labyrinth has would be the best possible outcome for any TD game, but this one for sure would top any. I give you my kudos, developers.
 "Kingdom Rush Frontiers"){kind=icon}
 "GemCraft Labyrinth"){kind=icon}
 "Astrox"){kind=icon}
linux DL coming soon.