My 24 month old loves this, he is mad for peppa pig and after only 4months of playing with this toy he now knows all of his letters. There are other character phonics toys out there like fireman sam that I would definitely recommend. If your child is interested in the character then they concentrate more and the variety on different games on it help your child at whatever stage they are, from beginner to intermediate.
For beginners there is a sound option that makes the sounds of the pictures. Getting harder is a follow the lights game. Find the pictures game, then find the letters and lastly can you spell game.
I have now bought flash cards to test him too, which he loves, and you can pick a pack up very cheaply. I would recommend getting some with capitals and lower case so your child gets used to both.
I've also recently bought him leapfrog letter toys, which initialy caused confusion as they used different examples for each letter for example, peppa says h for house and leapfrog says h for horse, but after some practice he's got the hang of both.