I've taken my son to Coffee and Scream many times. It's a great place to take toddlers and preschoolers and we always have lots of fun. I love that he can be so independent there at such a young age.
It can get pretty busy particularly on Fridays mornings. The afternoons are always less busy than the mornings (it starts clearing out about 11:30). It opens really early (7am) and there's hardly anyone there so if you have early risers, it's a good option too.
The kids menu has good made to order options (real mac and cheese nor KD) that kids would like eat and moms would like to order. And the prices for them are really reasonable. My favorite thing to order for both of us is the Egg screamer which is like a really good Egg Mcmuffin.
They do offer WiFi but you need to ask for the code at the front. It is my favorite indoor play place for toddlers in Calgary.