I don't think there is a lot of information out there about these instances, so i thought i'd share what i know. (I realize the first reply will probably contain a like to a place with much better info :)).

M.A.R.I.O.V.R.

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The Mario instance has two missions inside (don't try to complete them at the same time):

Basic run
All you have to do to finish this mission is reach the end of the obstacle course. There is no time element involved, so don't worry if you fall down a few times.

Repeatable: ever 21 hours
Reward: 1 cyrene mission token

Advanced run
This one is a bit trickier, first because you have to pay one Imperium Key Cube to start the mission, and secondly because this is a timed run where you have to finish within a certain amount of time.

The reward is random (not only based on time).

Repeatable: ever 21 hours
Reward: either a few cyrene mission tokens or a Jade Fragment.

jade.jpg

The jade fragment can be used to start doing the L.U.I.G.I. instance mission (you won't loose the fragment).

 

 

L.U.I.G.I.

luigi.jpg

This run is a lot harder, be sure to practice it a few times before you do the actual mission.
Apart from all the jumping you'll face two new challenges in this instance:

  • A floor that gives you damage as a percentage of your current health.
  • Imperium mobs that don't like you jumping around

There is one mission in this instance, and it is off course to reach the end of the obstacle course alive and on time.

Required to start mission: 1 Imperium Key Cube (consumed) and Jade Fragment (not consumed)
Mission Reward: Cyrene Mission Tokens

It was posted on http://cyreneforum.com/threads/mario-and-luigi-instances.6930/