Looks good, downloading now.
My only comment before playing it would be work on the terrain, the first picture across the river, really could use some work. Will update after I play it.
EDIT:
It was fun to play, but it was also very pointless.
It started off very fast, which I do not mind since I know the controls, but if you plan on selling you really need to have some sort of waiting period where the player can adjust.
The gameplay was fun, liked that you did not use the default guns, even if you did not make them yourself, it was still a nice change.
Nothing made sense though, why would a a shooting range be facing the ship with no backstop, why would the key be on the ship? I could go on longer, but you get the point.
The terrain is not good, I will put it straight out, its no good.
The trees on top of the hills need a lot of work, I really do not think you need them there
Although I am being harsh, it was fun to play, and you made a fun game, I just do not think this belongs on the showcase forum yet, as I believe it is still a work in progress.
Keep going as I feel this has potential just a few beginners mistakes.
Also, the launcher did not work for me, nothing happened when I selected the level, had to open the level manually.