Did you know?
I See Red People
One of the many player rumors about MK2 that was actually true was the random chance for Johnny to perform his Shadow Kick with red shadows, instead of green. Though the exact science behind it was never deduced in that game, both the red shadow kick and red shadow uppercut would become regular special moves in Mortal Kombat Trilogy.
Non-Smoking Section
In the emulated version of Mortal Kombat II included in the Xbox and PlayStation 2 action game "Mortal Kombat: Shaolin Monks", due to Pause being configured on the controller as Start, it is impossible to fight against Smoke. The irony in this, is that in order to unlock MKII within Shaolin Monks, you must complete a series of quests given to you... by Smoke.
This flub was also present in Midway Arcade Treasures 2's emulation of the game, but the irony is lost there.