Unless you were there it’s hard to imagine the hype that came with these simple handheld games. Each was an LCD screen with fixed images, surrounded by buttons and a shiny screen. Some were even foldable with two screens.
Today’s controllers still have the d-pad on the left and action buttons on the right.
Clearly precursors to the Nintendo Gameboy and even controllers for PlayStation 1 and beyond (minus the screen of course).