I wonder what your definition of "short", considering the price of the game (surprise, it's free!) and the overall average playtime length of video games. You seem to emphasise that word a lot...
It said it was a short game with an average session of a few minutes. Just because it's free, it doesn't mean I have to like it. Do devs want real feedback or do they want their balls sucked? I don't have to praise every free game I play just because it's free. I also ran into a bug that got me killed after 2 and a half hours of playing. I think I'm allowed to be annoyed.