We tried it last week. My DD 4 was a bit confused since she can't read yet (I had to help). My DS 10 really liked it.
At one point we were in the United Kingdom trying to activate something (won't say what) and my daughter pushed the OK button on the Kimmunicator. Winnie the Pooh and Tigger popped out of a door to go to a character spot. For a couple of minutes they played with my DD. She thought she let them out of the door.
At some point they will either add/change this to be a Phineas and Ferb thing.
I recommend it for your 5 year old with some help