Hi.
I dowloaded the demo, and I'm liking it. However, I can't seem to control the vertical movement. The tutorial says "shift + left mouse", but that doesn't do anything. Shift switches the cursor from an arrow to an arrow with a tiny box beneath it, but when I rightmouseclick then, it's just horizontal movement.
Am I missing something? I'd buy the game form GoG, if I can get past this problem.

Nope. Not game breaking. The worst thing that not being able to change your verticle position will do for you is force you to go around an obstacle instead of over or under it. Just be careful that fighters flying in an escort formation don't crash into any space stations, and you'll be fine.

When you want to change your vertical movement hold down shift then click on the screen and scroll up or down, then release. It works just fine, no work around needed.

Alternatively, if you still can't get the hang of it, just press M and use that. A more redundant way, but way easier to use.