 "Reaction" received a generally positive response from critics. Eric Goldman of IGN, giving the episode an 8.2. rating ("Impressive"), wrote favorably, noting that the depiction Dr. Octopus "was very clever – on one hand, he was a pitiful, cowering pushover. But when Norman was berating him we got a brief look at the anger within, as he imagined attacking Norman with his robotic tentacles." Goldman applauded both Dr. Octopus'line, "I've been good" and when Spider-Man crashes into several stuffed animals, only to be pulled out by Dr. Octopus in a manner similar to a carnival game; he concluded that, "This show continues to leave several prime time live-action shows to shame when it comes to building serialized stories and has been one of the most pleasant surprises of the TV season."
