As it is free, it's definitely worth a play through.
I did have a problem with the ammo being a little too spare, since there is no melee option, and one spot had be stuck as I couldn't figure out how to continue for a while (I thought I was supposed to blow open a grate, but there was a button to open it.)
The graphics were a little sparing, but I thought the music was good. All in all, it was well worth my time to play it.