I'm assuming everything from the base sprite assets up was made during the jam if you're listing Aseprite in the software, and if so then its overall look and feel is very polished for a game made in nine hours. Especially if that includes music. The gameplay mechanics were good for a jam and the difficulty ramped up nicely; the only thing that seemed a little awkward to me was handling the weapon changes with numbers while moving with WASD (the mouse wheel seemed too imprecise), but considering how complicated the controls to Mech Squad will be if/when I get that game ready I'm hardly one to talk ^,^
Also props for replying "git gud" to someone who says the game is too hard.