I did see a couple of instances of enemies appearing out of place i.e. ships inside central islands and tanks floating in the air.
I think missions should be on by default but also think there should be more fanfare for completing them.
The level generation needs tweaking to ensure that the fuel pads are more evenly distributed both in terms of regularity and position: there's a stretch from bridge 2 where if you go right around the central island there's nothing but fuel pads, but going left there's none. Later on, I hit stretches where it seemed that no fuel was available at all.
And thanks for lowering the fuel pads into the water a little so they have the wave shader :-)
I'm not good enough to have made it to a boss yet :-( Maybe add a boss rush mode?
