Hey, Strzyga, I like your game concept!
It has a simple but funny gameplay, a good art style and sounds/music fit perfectly. I really liked it.
In order to help you to improve it, I suggest to "stick" more with the theme (phone call). For example, for each level, before starting time you can put a ringtone and a random dad's sentence (something like, "Hey, Junior! Come to see this cosplay show!". And you can consider that maze like a big mall and include some "obstacles" - people, shopping carts, pets etc.
You're going to right track, so... keep up the good work!