ah nice, was wondering what was in those entex card game... games. Surprisingly it's got that much horsepower in there, though they probably need it for the RAM to store the card deck.
Yes, gakken made a few of entex's games. Gakken actually made tons of handheld VFD games for various manufacturers, like those coleco tabletop games- but their name does not show up anywhere on the boards. The pac-man/ ms pac coleco tabletops are made by Gakken too and Gakken even released pac-man as their own game with very minor changes, in the same cabinet.