hi i have a game in google play called escape island survival duty. it's a platforming game made with buildbox 2d. i tried in this game to make a small journey in an isolated island where you should survive and complete the levels. in this game game you have a level where you collect keys to clear the level. the link : https://play.google.com/store/apps/details?id=com.escapeisland.survivalduty&hl=en
I once had the same problem and was able to solve it. Take a look at your advertisements and you may have a copy of the code with a space in it.