Yes, he is. He's the head of development for AG, so that means he's the head of game production. The games that has his name on it are all made by multiple people. Thank Jimp for the graphical work, which has made his games so iconic.
On the awesome scale John gets a 6/10. Mainly because I spent a lot of time playing Exit Path. It would be a 8-9/10, but he showed little to no support for Exit Path 2.