Hey,
I have checked out both Your available games with Android 9 powered device. Played couple minutes and found some issues:
Spot Race:
in game - minimize game, music stops - that's ok, yet when returning to game it goes directly to game, shouldn't it show pause screen or something
in pause - minimize game, music goes on, after returning to game it looks like music stops for few milliseconds and then starts playing again
saw one interactive add, it was playing without problems, so it's ok.
Greedy Mouse:
music doesn't stop when app is minimized, both for in-game and in-pause screen,
second issue: going to pause screen makes music a bit louder, resuming game get it back to proper volume
didn't see any admob advertisement for couple minutes of gameplay,
Beside that everything looks fine, Greedy Mouse is just not my cup of tea, but it's good game and it feels that a lot effort was put into making it.
Spot Race is very good little game, one thing that few times I had problem with distinction of some symbols. Surely it will stay on my device for playing it in future ;-)