Could it be that you are trying to sell “default projects” for 4 USD? (It looks like you just copied over the 3rd Person Character, The UFO and changed the Pawn…)
It even looks like “your” Car and UFO behave the same as the ones used in the Example-Projects. (in terms of movement and controls - and yes, i tested them a minute ago, really looks like identical behavior.)
EDIT: I am also pretty sure that there was already a discussion about your “BUY NOW!!!111” threads in the community-section.