I'm not a particular fan. The tutorial is quite slow but I do not find it an inconvenience after reflection on my part. His strength to assimilate too, at least. But I would have liked or wanted this to be faster when the radar makes a full turn. Maybe not during the 1st waves, they are quite long over time anyway. Either way, I didn't try to get through to the end. So hey, I don't have much advice to give. It's just me who doesn't appreciate it in my opinion. Even if it remains despite all a good mechanics of game. I have the impression and the feeling that something is missing which would give more impact. I don't really know what. Maybe make the interface with more information, make the screen vibrate, make it more "alive". Afterwards, I fully understand that the concept remains minimalist.
I think it would be much better to be able to differentiate distinctly the types of missiles to be launched according to the colors. And I think the sprites are not showing. From what I see here in the screenshots.