I have found several problems with this game so far.

1 in particular could be the reason you are having trouble with this game. The game seems to behave in a strange way, be it design or sloppy programming.

Anyway. While the game is running it seems to drop strange files into the root of the directory.

Example:

F:\t15.5


But then it looks like (and I hope) it removes them when you exit the game. This is rather bad as no game should be doing this. It can screw up once and damage an entire machine's drive. But how it pertains to you could be the UAC, assuming you are on a windows operating system.

The design of UAC is to prevent malicious software from dropping files in areas you didn't allow them to be placed into.

I shall be informing GOG of this shortly in a complaint about it. You should talk to them as well. Oh and you should NOT have to turn off UAC just to play a video game, nor should it be bypassed if they direct you to do so. It defeats the point of having it turned on if you want it on. Besides, games shouldn't behave this way >_>

I get this issue sometimes. It seems to take some time to get the game loaded up properly. I actually watched yesterday as the memory allocation ticked up and up in the process view and after 15 seconds or so the launcher was loaded.

So, try giving it a bit of time?

The game has a weird launcher which takes some time to load up.
In addition, if you open a file from this launcher, let's say the starter guide, it might count as Xenonauts as well (at least on steam).

Just to make sure everything works fine I'd restart the PC, start Xenonauts, do nothing but wait for the launcher to appear and click play. It should work perfectly fine that way.

You may want to look at the thread I made. While I don't have this problem of it taking a long time to launch.

What I can infer from your information here and what Chris told me in my thread, is it may have something to do with the game automatically checking online for the updates and RSS feed and whatever else it is doing(i do not know as I didn't write the game code).

If the game is taking, say, longer than a 60 seconds...then uh. Yeah, definitely look at my thread here on the xenonauts forum area and politely ask him to look into what maybe done about the Launcher.

I have already asked if he can add a toggle option to allow/deny the launcher to automatically go online. If you like this idea, please let him know.

Only way for the game to be better than it already is, is to give feed back =)