Its keyboard is just for show (much like its older stablemates) but you can play a library of 25 built-in games, not just those released for the 400, but also Atari 800, XL, XE and 5200 titles.
One was the Atari 400, now reborn as the Atari 400 Mini. The folks at Retro Games have form in this area, having previously put the C64 and Amiga through a hot wash. I had mixed feelings about those ...