Ah ok, yes then i think it works. Just expected, that i maybe have to collect it also after shooting it outside of the bubble or so. Maybe you could add a little visual feedback or so. Just that players know what's their effect (or just write the effects next to the icons on your game page).
About the shop. Yes, i detected it more or less by accident as i wanted to leave^^
I mean, if you maybe plan to release it as a real game and put some IAP stuff in it or so, you should maybe show it the players a bit more prominent. But for the little game jam, i rather found it as an "easter-egg", which then just was a very nice surprise at the end :-D