First, thanks for your comment!
I'm surprised how many people said I should have put strict boundaries to the level. For me it was really intentional to keep it this way. The reason is, if you get cornered against the border of the screen, you can still take some kind of "leap of faith" and dodge missiles by going out of bounds. It's risky because you can see your mech or some of the rockets, but if you do it right it can save you. I like it because it goes along that feeling of being in space. And it's not really a problem that you can go pretty much as much as you want out of bounds because a round only last ten seconds, so you can't do that infinitely, and the rockets will continue to follow you, so even if you don't see your mech you can know where it is by looking at where the rockets are going.
I think the problem at the moment, maybe, is that it feels unintentional. I was planning on adding gameplay around it (being out for too long would reduce fuel over time), and some feedbacks (an arrow showing the direction of you mech. I dont think the arrow is necessary, but the fuel thing would help player understand that it is intentional, I thought about that.
Or maybe people tell me about this because they really don't like it x)
Anyway, I went on too long. Thanks for playing, thanks for taking the time to comment, I'm going to go try your game right now!