I like this game! The gameplay is varied enough that I don’t get bored, and the “prizes” aren’t items that are necessary for completing the game. I also like the inclusion of the coloring pages! I think it’s a nice touch that makes it more fun and motivates the player to complete more regular levels.
Excessive ads in free-to-play games like this normally don’t bother me. However, I take issue with this game because the ads interfere with the gameplay. As far as I can tell, the ads in this game play almost randomly with no fixed amount of time between them, and no matter what’s happening in the game. This means that, for example, I can be in the middle of moving my brush to a section when my movement is interrupted by an ad - then the game mistakes my brush stopping for picking an area to color, and I can screw up half my progress in what is already a short mini-game. Most apps with a lot of ads like this play them, for example, every time a level is completed. This way, the user knows to expect the ads, and they don’t change anything about the game itself. I think something like that would improve the user experience of this app a lot. The games are short enough that you would probably see a similar number of ads relative to how long you play, just with less disruption of the game itself.
Tl;dr, the ads are unpredictable and it gets in the way of the game.