The game is really really simple. Like the "made in 24 hours" kind of simple. The concept was very clever (AwkwardSilence777 got it right imho). But... that's it. That's not enough to make a full game. (something with enough replay value to be worth it for me to take my phone, open google play, search for your apk download and install it). The 4 stars are because i'd love to see this develop to a full game, it has a good potential, and the other .5 is because it's very polished, the graphics fit together nicely (except maybe the bouncing game over screen, that's a little childish i think)... Keep working on it!
(For example, what about making the game horizontal and adding a "jump" option? Also, as someone suggested before, medikits would be nice)
P.S., Pizza, FTW