At the turn of the 21st century, a slew of retro-based handheld plug & play systems were released. These systems would usually contain a number of built-in games. Some of these systems would abandon the handheld form factor in favor of a loose recreation of the original retro system complete with their own controllers and powered via AC adapter rather than batteries. These dedicated systems would continue to release on occasion until 2016, when Nintendo released the NES Classic Edition (and Famicom Mini) which kicked off the trend of mini consoles. The mini console trend eventually cooled down by the end of the decade.