At a glance, 'Prototype' and 'Infamous' appeared identical. Only their marketing teams could help consumers tell them apart—and choose one over the other.
I really liked this article, partly because its a deep dive into a thing we don’t hear about often (marketing!) but also I like both games. I remember at the time critics were comparing the 2 a lot, and the consensus that I seemed to get (mostly from Giant Bomb which is the site I was primarily following at the time) was that Infamous was a better game. Having played both though I vastly preferred prototype. As the developers said in the article though, the gameplay of the 2 is actually quite different.