Nice analysis, and cool to see how simple it is to get quite a satisfying effect. Also quite fun to see that the level symmetry was indeed exploited multiple ways to save space. If the author is here, they write '"@123" are the first 4 entries in the default c64 character set' but likely meant @ABC.
In two player mode, still even today, C64 Bubble Bubble is one of the best casual games. I can sit down almost anyone on the couch and they'll enjoy at least a few rounds, experienced video game players or not.
That the game design and implementation cuts through FOUR decades of time to be enjoyable says something. There are many old games which still are good but not as accessible to a modern audience.
There are even more old games which are impressive even in retrospect, but don't play well today.
Was the C64 version available as a cartridge or did you have to load it in via the painfully slow floppy drive or worse off of a tape?
An advantage of the NES version is you could be playing it within seconds of hitting the power button, which made it great for casual pick up games.
Is there anything specific about the C64 version that sets it apart from the arcade, NES or other versions? As for design, old arcade games had to both look and be fun fast in order to earn your quarter. As for implementation, the story goes that the original source code for the arcade game was lost and all ports had to be done by reverse engineering an arcade board.
c64 was just so much smoother playing + looked better visually. not choppy.
Indeed, my kids who are 5 and 8 enjoy it about just as much as Mario Kart 8 - especially the earlier levels which require less of the balloon jumping.
Bubble Bobble, arcade and ports, were wildly popular especially in the UK, to the point that when I was working as a game dev in London in the early 2000s if you mentioned what you did to a random person the chances were they would start lamenting how complicated these modern 3D games were and how after a bit of digging it would turn out they just loved Bubble Bobble/Rainbow Islands etc.
I think it's up there with Asteroids, Defender and Robotron honestly.