My full game single segment speedrun of Pokemon Blue in 1 hour and 58 minutes, without glitches, as set by SpeedDemosArchive standards, Marowak ghost skip is not considered a glitch, whereas walk through walls, ZZAZZ, save corruption and underflow to level 100 and trainer fly obviously are.
Happy that I finally got sub 2.
This run was performed real time in a single segment on a Gameboy Player, with the border edited out in preference of the actual screen. For reference, as I've had numerous queries about this, the battle animations turn themselves back on for the final fight, that was no glitch and there is no cheating in this run.
The Marowak Ghost Skip is not considered a glitch as the Poke Doll is simply acting on it's intended purpose, to flee from a wild Pokemon battle. I'm fully aware others label this as a glitch, but I did not set the grounds for this run, I simply ran the game. As long as everyone plays on the same rules it doesn't really matter, right? :)