Cool old school FPS game! The shoot mechanic was very satisfying, and also the game felt very responsive, which is really cool for an FPS!
The usage of the art assets is clever, I really felt lost in a desert, where I have to fight for survival.
The only criticism that I have: it is when a scorpion is behind me, and I want to turn in order to kill it, I couldn't, indeed, each time I was instant kill, which was a little frustrating.
Apart from that, your game is really nice!