I wish the game would tell you when it was over.
I reached the point in the game where I heard nice music, but no one else showed up at the gas station.
I also wish there was a point to the clue on the guitar. Sure you have the ability to keep pumping gas till you're so bored you start shooting people, but you gave us two other things to mess with. Earphones and a guitar. Though I like the interaction with the guitar, it's not clear why we need the earphones. In either case, we can't progress without turning on the radio.
58.3? Sure if I was able to switch channels. Is the objective to get to that channel? I noticed that the indicator shrinks towards a stronger signal everytime you shoot someone.
If there was another branch we could use....like say using the messages by the customers to justify a shooting or not...or perhaps going down a peaceful path, or the ability to dent the car/spill gas on a customer/serve them an extra item from the store/or tell them to leave altogether, then that would definitely add a level to this game.