If you look at how game technology evolved, the strangest and most astounding thing I found is that years ago you had to pay 50 bucks for a video game cartridge that's essentially one educational minigame (in the NES version 2) where as Sesame Street's website offers a bunch of better games for free. And fully voice acted as well. Remember how amazed we were with the fuzzy soundbites in Big Bird's Hide and Speak and Countdown?
I don't feel like posting it here, but there was a review I saw for the Elmo's Number Game for Playstation that fairly says something to the extent of yeah, this is a game for kids and it's supposed to be educational, but it isn't and it's not fun on any level.
Aside from that, the original game in question for this thread was essentially a 50 dollar toy piano. Unfinished or not, it seems like something a small child would get bored with quite fast. Egg Catch was fun, and plays like a video game (albeit a simple one), but if this was released, I don't see it being popular. It would have probably worked as a computer game, though.