Journey Escape. Master console portablizer Ben Heckendorn made this portable NES/Atari monster out of an Atari Flashback 2 and a "NES-on-a-chip" found in many Famiclones and joystick-based TV games.
The placement of the Atari cartridge slot is a little unfortunate, but we're sure he wouldn't build a device with an unusable screen, so we doubt the cartridge obscures the view too severely. Cramming two whole consoles and four rechargeable AA batteries into a tiny handheld takes some maneuvering!
Seeing Ben's work always makes us want to learn electronics. It also makes us want to play old games-- guess which one we end up doing.