I'm a massive Muppet fan, so by extension, that means I'm a Sesame Street fan. I grew up on the show, sometimes watching all three broadcasts (morning, noon and afternoon), so I'm not ashamed to admit that my face absolutely lit up the moment I saw digital versions of Elmo, Cookie Monster, Grover and other well-known Sesame Street characters pop up on my screen. I thought it was neat, the kids I played with thought it was amazing... so what more do you need?
Double Fine did a great job at translating the furry puppets into digital models. There is some noticeable matting to the fur, but enough of it stands out that from a distance, some of the monsters look like puppets. The effect is pushed even further with animation. Characters move like puppets rather than digital figures. The walking looks off, though that is because we rarely see Muppets from the waist down. The most impressive of the bunch is Grover, who has just the slightest of shake after all his movements, nearly mimicking his real-life movements to the letter.
Once Upon A Monster is packed with voiceovers from the cast. Characters always address players directly, which is a lot of fun. Dialogue is in tune with normal Sesame Street skits, so there's something for kids as well as a few in-jokes just for the parents.