Diffiuclt to lock in place

My 2 year old son really wants to play this game,but he get frustrated with it because he gets the shape close to where it fits- not quite exact, but very close and the piece goes flying back to the starting point. It frustrates him as well as me ( I just want him to be able to play by himself for a few minutes!)
I try to show him how to lock it in place, but if it is not exact when I let go it flies away.
Please help the puzzle pieces lock in place like they do in shape builder. I try to get my son to play shape builder as this game frustrates him, only he really wants to play this game.
Also I am disappointed with all the ads and the ease of which my son can enter the app store. I already own all of your apps. I prefer the apps that make you go to iTunes to download the other apps. Thanks!

clear2me about Animal Preschool Shape Builder Puzzles - First Word Learning Games for Toddler Kids Explorers by Abby Monkey®