While I was thinking about how The Oil Blue stands out from other games in the time management genre, it reminded me of Tower Defence games, and the fantastic Immortal Defense. The gameplay feels far less restrictive than the typical TD, and it's accompanied by a pleasantly unconvential style and soundtrack, and most unexpectedly for a TD, an engaging storyline.
Platforms: Windows
Website: http://studioeres.com/immortal/
Greenlight page: here