sorry for the newbie question, but what version am I playing?

I d/ld xenonauts for the first time today through desura, and my launcher says "v18 hotfix 1 -4 april 2013",

but that makes no sense because since then there's been updates.

so.. what version am I playing really? is the text in the launcher not updated? is the version really old? why am i playing an old version then and how to get the new one, etc etc thanks!

Downloading the standalones is usually the best bet. They'll be the downloads along the side of the Desura page (from the actual Desura website.

Then download the hotfix 2 from the Announcements subforum. Or wait from V18.4 to be authorised, which should be soon.