Introduction to Pac-Man and its Ports
When Pac-Man was released in 1980, it was one of the first games to truly break into the mainstream. Its innovative design which differed significantly from the Spacewar! and Space Invaders style games helped it to become a bit hit in arcades. Naturally, ports to home consoles and computers started coming out in 1982. Atari received the console and computer distribution rights for Pac-Man ports and initially released Pac-Man on their home consoles and computers at the time. Specifically, Pac-Man on the Atari 2600 was a massive sales success, however it faced a lot of criticism for being very different from the arcade release, with a different maze layout, color scheme, and different ghost AI. Many people consider this to be the worst video game port of all time, but the game did have its fans and still does today. Personally, I think it actually stands out as one of the few Pac-Man ports worth playing today due to its unique maze layout and some gameplay differences. It is undeniable however that Pac-Man on the 2600 differs significantly from the arcade game in many ways, and most people who bought it back in the day were most likely looking for authenticity to the source material rather than a game that's more of a unique spin on the original.
I personally find the differences between Pac-Man ports fascinating, especially because each one worked around the differences and shortcomings of the hardware they released on in various ways. One of the biggest differences programmers had to consider is the screen aspect ratio. The arcade release of Pac-Man used a vertically oriented screen, however the televisions and monitors of the era were horizontal and thus not well suited to such a game. Most modern Pac-Man rereleases emulate the arcade game and either leave black borders or artwork on the sides of the screen to compensate for the taller aspect ratio, but older systems couldn't do this very well due to lacking in screen resolution. Many ports simply stretched the maze to fill the entire screen, such as the Atari 8-bit/5200 port of the game. Others move the score, lives, and level counter to the right side of the screen and leave the maze on the right, usually shrinking it down somewhat. The MSX and NES ports took this approach. Another common approach was to simply rotate the maze on its side so it would fill up the screen horizontally. Many Japanese home computer ports did this. Lastly, usually handhelds would scroll the screen to allow for better detail while keeping the game within the limited resolution of the screen.
There actually was one other approach taken much more rarely, which was to redesign the maze to better accomodate the screen size. The Intellivision port, for example, made the maze slightly smaller to accomodate its low resolution. The 2600 port used a repetitive layout which was easier on the limited specs of the console. The only other port I know of which did this was released on the Commodore VIC 20.
The VIC 20
The VIC 20 was a home computer released by Commodore in 1980. The goal with the VIC 20 was to make an affordable home computer which could also play great video games. It had much better sound and graphics than most previous computers of the late 70's, such as the Apple II and Commodore PET. It ended up being a huge success for Commodore and spawned many games. Despite being advanced in many ways, an infamous shortcoming of the VIC 20 is its lack of sprites. To do any sort of moving graphics on the VIC 20, the programmer would need to constantly redefine graphics characters to give the illusion of movement. With some clever programming it was more than possible to make great arcade style action games on the VIC 20, however it would have required a programmer who understood the hardware. Oftentimes instead of having smoothly moving characters, they would jump from one character cell to another because it was simply easier to program, especially considering the VIC 20 didn't have much RAM to hold a lot of code for moving characters smoothly.
With all that out of the way, it's time to talk about Pac-Man on the VIC 20, released by Atari in 1983. To help get my points across, I suggest pulling up a gameplay video of Pac-Man on the VIC 20 such as this one so you can better understand my criticisms.
The Port
After starting the game, you'll immediately notice the maze is significantly cut down compared to the original. This is understandable enough due to the limited screen resolution, although certainly not ideal. It would have likely been more than possible for Atari to have included the full, uncut maze (foreshadowing?), but this does the job. This does inevitably change the way you will play the game, especially if you're deeply familiar with the original layout. It also means there's less room to run from the ghosts, so you need to be extra careful.
The next thing which will likely happen is you'll immediately die to Blinky, who will go to the left and down and kill you. If you're well versed in the Pac-Man ghost AI, you'd know the ghosts start the game in "scatter mode", in which they all go to a corner of the screen and move in a circle for a few seconds before entering "chase mode", in which the ghosts more directly chase after Pac-Man. Having the ghosts scatter at the beginning allows the player to get their bearings and means the ghosts won't immediately come after you if you don't immediately start moving the joystick. Unfortunately, the ghosts don't really seem to have a scatter mode in this version of the game, and because there's not really much room for you to go, if you don't immediately move the joystick to the right, you'll get jumped by Blinky and lose a life.
After I immediately died on my first life, my next thought was "Okay, I'll just go down the corridor directly below Pac-Man by holding the joystick downwards before he starts moving." If you also thought to do this, congratulations, you've most likely gotten yourself killed a second time, and that's because turning is awful in this game! Instead of moving downwards, Pac-Man will just move to the left and likely get killed if you don't react fast enough. To actually go downwards, you have to let Pac-Man go left a bit, then move the joystick to the right, then move it down. Another little thing that helps to make the situation even worse is unlike the original, every time you die, the full Pac-Man jingle plays. This quickly can become irrirating, especially if you get handed a bunch of cheap deaths quickly.
The thing that turns this game from not great to hot garbage is the turning. If you've pulled up a gameplay video as suggested, you might have noticed that Pac-Man turns in a strange way, as if he jumps from one position to another. You might also notice if Pac-Man hits a wall, he doesn't actually touch the edge of it. This is caused by the VIC 20's graphical limitations. It's almost as if the game was made for an LCD handheld like the Game & Watch, where instead of a dot matrix screen, the game is lighting up parts of a pre-defined LCD to show movement. This makes turning feel very strange and choppy, and also causes you to miss a lot of turns, which often gets you killed. Cornering in the original feels very smooth. You can zip around corners and turn quickly, which feels very satisfying. This is not the case in the VIC 20 port. One especially infuriating turn I often failed was parallel to the bottom Power Pellet corridors going up to the way which has the screen wrap tunnels (sorry if I didn't explain that super well). This makes you take two sharp 90 degree turns one after the other, which is very difficult in this game but effortless in the original. Something else to keep in mind is you can't hold a direction while going through a tunnel to queue that action for when you get to an intersection, which also really helps to make turning in this game feel awful. Most deaths I got in this game were from bad turning.
The last big issue which I find holds this game back is the miscellaneous graphical issues caused by poor design choices. A big one that baffles me is when a ghost passes through a line of Pac-Dots, the two dots to the left and right as well as above and below the ghost dissapear for a moment. This can make it kind of annoying to tell where there are dots you need to eat. The second graphical issue is the color cell clashing. On the VIC 20, each character cell can only have one foreground color and a global background color (black in this game). This means when something happens like a ghost passes through another ghost, the color cells will clash and it'll look off. Another weird thing that happens is the dots next to Pac-Man will turn yellow. I think Pac-Man is two character cells wide, which is probably what causes the weird turning as well.
The Jelly Factor
With everything I've presented thusfar, I think it's safe to say that the VIC 20 port is probably the worst Pac-Man port out there... but it gets worse. You know how I said it probably would have been possible for Atari to include the full, uncut maze into Pac-Man if they really tried to? Well, that's because HAL Laboratory already did.
For some reason, Commodore had decided to release the VIC 20 in Japan before the United States, despite being an American company. To help give the "VIC 1001" as it was called a solid library of hit arcade games, Commodore got the license from Namco to publish ports of their arcade games exclusively in Japan. This included Pac-Man, Galaxian, and Rally X. These ports were developed by HAL and were very good ports of the originals.
Commodore knew these titles had international appeal, but since Atari owned the rights to distribute Namco games overseas, Commodore tried to get around this by renaming Pac-Man to "Jelly Monsters", Galaxian to "Star Battle", and Rally X to "Radar Rat Race". Of course, Atari saw right through this and sued Commodore, forcing them to pull the titles off shelves.
So, the game we got as "Jelly Monsters" overseas was actually a version of Pac-Man by a completely different developer. And, it turns out, this port is absolutely excellent compared to Atari's port! The issues with turning, ghost AI, and the maze are all completely non present. It goes to show that with some more effort, Atari could have alleviated many of the issues Pac-Man suffered from. Just the fact that a better version of Pac-Man already existed when Atari released Pac-Man in 1983 really hurts this port even more in my eyes.
Epilogue
Thankfully, when it comes to Pac-Man and Pac-Man clones on the VIC 20, things didn't remain all bad for too long. Commodore eventually released Cosmic Cruncher, which is a very blatant Pac-Man clone that's just different enough with a different maze and characters to avoid Atari's lawsuits again. Even Atari themselves released Ms. Pac-Man, which was actually an excellent port and one of the best games on the system. If you're interested in playing a Pac-Man game on the VIC 20, you do at least have options.
Compared to the Atari 2600 port, I think the VIC 20 port is worse in almost every way. The only improvements the VIC 20 version has over it are the more accurate colors and sprites and the slightly more accurate maze layout. Honestly, playing the Atari 2600 port sounds a lot more fun than ever touching Pac-Man on the VIC 20 again.
By the way, if you want to play VIC 20 Pac-Man for some reason, try beating my high score of 22,950! Let me know if you can do any better!