I see, the cards... I don't know why but I didn't notice that I was picking them up until you said that. Maybe a stronger indication for the pick-up could be good.
Also the menu screen with the song I thought was great.
EDIT: I tried again.
I still didn't get the mechanic with the cards. What do the numbers mean (maybe a joke/puzzle that went over my head) and which one am I supposed to find next.
Also I realized that the first card is actually grabbable, but it's hard to reach it because when I press jump to get to it it teleports with the phone booth instead.
So that way it's almost like a tutorial moment that is missed. I think if it was grabbable easily at the start then players could realize that it's possible to grab them.
Sorry if this is more feedback than you wanted. Still curious about the game!
EDIT 2: This is an insane game. I like it! Once the cards became grabbable - I don't know why that happened - it became a lot more fun. Enjoying all the weird ideas in it.