I've seen and played some Moppet Video games back when they were actually in production, around 15 years ago (1986 or 1987). There was a Chuck E. Cheese
in Redondo Beach
that had several of them.
I don't recall why I had been in that area, as it wasn't anywhere near my home, but I know I was walking home for some reason. I had a few quarters in my pocket, and decided to stop into the Chuck E. Cheese to see if they had any new games, and kill some time. I saw these little waist-high games, and decided, "what the heck." I walked up to them and checked them out. I remember that they had Tugboat, Leprechaun, and Noah's Ark. They were so small that I had to kneel to play them.
I dropped a quarter into Noah's Ark, amused at the idea. I found that I was playing Noah, and my task was to collect pairs of animals, and bring them to the ark. Simple enough that even a 6-year-old could do it (Which, of course, was the whole point of this company's games). I played the game for nearly half an hour before getting bored and leaving.
The game starts off with a couple of pairs of animals and a slowly-rising flood (It's a vertically-scrolling game, with the Ark at the top, and the water slowly reducing the playfield). Each level gets progressively more difficult by adding more and more pairs of animals - if I remember correctly, the higher levels have fantastical animals like unicorns. The game's strategy was in that you had to collect BOTH of a pair of animals before you could take them to the Ark. If you collected one, and the other got swallowed up by the rising flood waters, you lose. That's the ONLY way to lose, in fact... get stuck holding one of a pair of animals after the other is lost.
I suspect that the purpose of the Moppet Video games is to keep young children who aren't old enough to understand the complexities of "normal" video games busy for extended periods of time, so that their brothers, sisters, and parents can enjoy the rest of the video games without interference. They can't have been very profitable, with how easy they were.