The very 1st thing they need to work on is the script. Because that is the foundation and it couldn't be supported by a bad foundation.

Let's see here they need to have fatalities, better acting,better characters,better script,BLOOD!,so alot of stuff needs to be done.

1 word.....COSTUMES!!!!

They need to have a well written script and storyline for the movie. Also they should try to keep the characters to a minimum. In MK:A they tried to shove everyone in there and it was a disaster.

in MK:A, there were lots of side characters, that were in games. And all the fans thought of them as main characters without a big role.

movie needs...

a good cast. Use Emmanuel Seigner.

not to rush anywhere with story, take the time they need. Most classics are long movies anyway.

to oversee it against the little annying flaws, like 'who opened the door? It was just shut' or 'she went this way... though no spider nets are broken by her'.

if they really are going to base it on MKM: SZ, and IF they really plan to show us hell and stuff... how about have some good quality satanist advise the movie? It's only done good for movies so far.
Or just have a MK fan, ONE fan, advise them. One fan has one vision. Many MK fans have many visions, they mix, and out come none of the visions.