Superb style. The art is simple but it feels so good. The theme interpretation is interesting, it is not just about countdown but also timing. I do not know why it was so hard for me to aim, really hard. Specially with targets that are far away, no matter if I take a long time to aim. I felt a little uncomfortable not being able to click to shoot (I just jump).
BTW, it is a good thing to think about linux player but in fact the game in linux might have problems. I had a segmentation fault. I was running it with firejail though, so do not take this info as 100% reliable.
Very good overall. The whole experience is very consistent. As I said it has its style and look & feel. Excellent job!