I tried this on mobile and it just wasn't playable in my opinion. It was way too difficult to click up and down and I ended up not being able to play for more than a couple of seconds at a time. On the PC it's much easier to play.
It's a very nice and simple game. Very good artwork and everything else is very clean and smooth. The only complaint at all is that I think it needs to be more clear where you can put the stickers in the how-to.
It seems the first store behind the pillars, even though it looks like every single other store, doesn't count as a store and you lose points. Even though the very next one that's identical counts.
The game is fun because of it's simplicity, but adding little point multipliers, shield upgrades, more medals, etc... would make this more challenging and have more replay value. As it is the only real replay value in my opinion is just the newgrounds medals. I now have all of those so I'm unsure if I'll play it again.