NES cartridges typically run in 5 volts., but the boards they used for the first batches of NES Rugrats only have 3.3 volts. Limited Run is well aware of the mishap and are now offering free replacement cartridges for those who purchased the game awhile back. If you bought Rugrats from Limited Run contact them so you’d get your replacement copy.
Here is a screenshot of the news courtesy of Cheap Ass Gamer from Facebook.
David Medina is a hardcore gamer and Japanese import collector owning dozens of systems and games from Famicom to Nintendo Switch. He has an active YouTube channel called "The Karnov Jr Show" and posts retro gaming content there weekly showing off collections, random store tours, and gameplay clips.