5 Stars for sure. The movie is absolutely fantastic, watched 10 times already and had lots of fun.
I`ve been waiting for this movie since I got my first MK game which was MK4 for Nintendo 64 back in 1998, and watched the 90's movies also. While I still love the 1995's movie, this one met all my expectations, it actually exceed them. It is not perfect, and there are a few things that are quite stupid for a MK hardcore fan (like the way they find and activate their power, not gonna give spoilers), but overall it's very good indeed.
The story is week? Yes. Character development is bad? Yes. They changed some crucial components of the story? Yes. But the fight scenes are great, we've got good fatalities (flawless victory!), special effects and cgi are good, it's great fun! My advise to you is, just go the cinema, ignore the plot issues and enjoy what you are there for: fights! It's mortal kombat bro!
If you are a MK fan and not a bloody critics (no idea what's wrong with these guys to give a freaking 5 in rotten tomatoes so far), you will have a great time watching this movie. Kongrats to everybody involved and looking forward to the sequels.