The Verge has a detailed article about this game, Hidden Through Time is a relaxing yet challenging puzzle game.
Hidden Through Time is a game where you locate hidden objects in a scene, similar to 2017’s Hidden Folks, the Where’s Waldo? books, and the puzzles inside the Highlights magazine at your childhood doctor’s office. It’s about as simple as a game could be: it presents you with some objects, animals, and / or people at the bottom of your screen, which you have to locate. Once you’ve found enough of them, you then move onto the next level.
Here’s the trailer.