WOW!!
Huge news!
Also thank you, Todd, for the MAME explanation. I was going to be really curious about how the heck this was possible on arcade but not MAME and now I don't have to be.
My apologies to Zerst as well, who has been arguing that 8-way steering was possible, and I was skeptical.
So the 4-way rule is now, officially, very important to enforce.
However, there's a big "uh oh" here.
Now that Todd has explained how to 8-wayify MAME, this opens up a major cheating opportunity.
If you can steer while climbing (and do it with the precision that a keyboard would allow) this is a HUGE issue for MAME submissions.
I am hoping that changing the source from 4 to 8 will corrupt INP playback. It should, and let's hope it does... if it doesn't we actually have a big problem now.