I like how the button started moving rather than just staying still. It made the game more interesting to play, however at one point, it began moving too fast and it was hard to click because it was moving all over the place. I think the strategy is to keep your mouse still and click only if the button moves close. I also think that if a sliding/moving animation was added to the button, so that you could predict where the button will go, it would add a lot of fun and deterministicness to the game!

Fun concept, the difficulty quickly amps up and can be hard to keep up with making it a pretty frustrating experience later on. It would have been interesting to have included different types of buttons that create different effects rather, such as double coins, requiring two clicks, etc. It would have also been useful to know what each item in the shop was exactly.