Feels repetitive. The execution is great, it's just that it turns into a grind for money. For a long time, the only boss zombies I saw were the fish thrower and the running guy. Was that just some random spawn generator messing with me, or is this game coded to only spawn different bosses after certain checkpoints? More variety would have been appreciated, I almost cheered when I saw a new boss zombie type because I was scared that I'd be fighting fish throwers/runners the whole game.
I'd feel a lot better about using the rifle if I was given a set number of bullets per battle that refreshes each day, rather than having to worry about conserving bullets across multiple days (especially because there isn't a reliable method of regaining bullets). Also, there should have been a little reload sound to let me know when it's ready to fire again. The rifle bullets also disappear when they reach the point they were shot at, which makes precision shooting a little difficult. The bullets should continue on in a straight path past the reticle (this is also an issue with the pistol, but it's less important because pistol bullets aren't as valuable).
As for the pistol, it took me a while to catch onto the quick reload trick, at first I thought the "R" just stood for "reload." You could emphasize the fact that it's a timing exercise by putting the R between vertical bars, like how most timing exercises look. There should be an option to disable automatic reload, especially because it can disrupt the quick reload flow. Failing that, the ammo count should hover over Rupert's head (along with health) so you don't have to divert your eyes up into the corner to see. I also would have appreciated if you could automatically fire bullets by holding down the mouse button instead of clicking repeatedly, because my arm got sore after rapid clicking sessions.
The damage mechanics were cool. It's a little difficult to tell when you can surf on a zombie or not, and I found that most of the time I never used kicking except to surf on zombies (which by the way was a very very weird idea, but that's appreciated). I personally think that you should have replaced RNG skills like "20% chance to kill by headshot" with something like "deal 50% more damage with headshots," but you made a valid design decision.
The only glitch I found was with the pistol's ammo. The pistol's ammo count wouldn't lower. It would shoot and reload completely normally, but the number wouldn't go down. The ammo count would go back to normal after a while though.
In conclusion, it was very cool and fun for about the first ten minutes. After all the smooth animations and quirky voices wore off, it just became a game about grinding for money.