Thank you for playing, nice to hear you enjoyed it. :)
NES games, in particular (perhaps obviously) Battle City, were indeed my inspiration for this one.
The sound was rushed few minutes before the deadline (including frantically composing the melodies), which is why is there not much of it. And there is any sound at all because I found some of my old code related to audio laying on my computer, there is no way I would manage to code it from scratch in the little time I had left.
There is also supposed to be an intro melody when starting the game, but it will only play on much older (I think 2-3+ years old) versions of browsers because the newer ones will prevent it and issue a warning "An AudioContext was prevented from starting automatically. It must be created or resumed after a user gesture on the page.", which is something I did not have time to notice, let alone find a workaround (which would be to wait for any user input (e.g. click or keypress) before playing it). The intro melody still plays (on newer browsers) when the title screen re-appears after losing the game.
This happened because I used only an old browser version to develop the game (so old that half of the entries submitted here will not work on it) because I wanted a great backwards compatibility, but I never thought that the forward compatibility might also be an issue with browsers. Now I am aware that it can, which is a valuable lesson I have learned.