From a computing perspective, this kind of makes sense. Japan uses NTSC and 60 hertz electricity, while Europe uses PAL and 50 hertz. Any game they release in Europe would have to be somewhat "ported" to run on the different timings without it causing weird bugs. If it barely sold in the US, it might have been "too Japanese to make sense to non-Japanese people" and they just suspended the European launch.

Yes and no. Some SNES games (as an example, since were talking Mario RPG) would receive 50Hz "ports", but they were often quite lazy, such as only adjusting level timers but not character movememt. Some games originating in PAL regions, such as Donkey Kong Country, would have more work put into getting them to run right at 50Hz.

But the vast majority would just run around at 5/6ths the correct speed and have huge black borders at the top and bottom. This was standard up until the PS2/Gamecube era, when gamers started catching on and demanding better ports or 60Hz modes. Then the shift to HD rendered the whole thing moot.

Mario RPG and other SNES RPGs not receiving PAL releases or receiving them very late probably had more to do with translation of such text-heavy games. I believe Nintendo at the time had a policy that all (big-name?) PAL releases would have to be translated into several major European languages. This was an issue around the PAL version of the Gamecube Animal Crossing game that was reported at the time, although that eventually did receive a release IIRC.

Japan has 60Hz tv, but their electrity runs on a split grid, eastern Japan runs on 50Hz and western Japan runs on 60Hz.

That I didn't know, thank you! That sounds like it could be messy though, I'd hate to move across the country and have to replace all my electronics lol

I beleive service voltage is unified at ~ 100V. Most electronics would be fine, as most electronics have a conversion to DC somewhere and that's unlikely to fail with a 20% difference in frequency. AC driven motors might not like to be moved, but might be OK given the domestic reality (unintended protectionism for stand mixers!). Line frequency clocks probably aren't sold in Japan or need jumpers/switches or would need to be replaced when crossing the frequency border.

Nearly all electronics manufactured today are capable of being powered (or are provided with power supplies that rectify to DC) between 110-240v at 50 to 60 hertz for that reason!

That way the variances across the globe don’t matter too much.

You still don’t want to take your expensive 110v hair straightener to the UK without a step down converter though as my wife found out the hard way!

It is a mess. Nowadays all devices support both frequencies, but I have heard from Japanese colleagues that back in the day if you moved accross the frequency boundary, you needed to replace your appliances. Maybe that's one of the reasons why Japan has a huge second hard market?

But the real problem came after the Tohoku earthquake of 2011, when several powerplants in the Eastern half of the country went offline, and they couldn't not transfer enough power from the Western half. There are a few conversion stations, but their capacity was not enough, and as such the Eastern half endured long black-outs even though the country had enough surplus power generation capacity.

Perhaps "thanks" to the situation, inverter powered appliance are common in Japan, like A/C and microwave

Fun corollary: Tim Follin composed his tracks at 55Hz, so they'd sound "right-ish" when both sped up for NTSC and slowed down for PAL