Greetings!
I am a certified and a highly experienced RC, Sim pilot and a professional Software Engineer as well.
I have completed all of the landing challenges with an “A” score except for this one. I believe that the code for scoring system in Nanwalek landing challenge has a few bugs which need to be fixed. After like 50 attempts, I haven’t managed to get 1 million points (A score) on this yet, my best score till date is 927,795 even after those 50 attempts 
Shouldn’t take that many attempts for a mature pilot like me 
This made me think if I was doing something wrong or there was something wrong with the challenge itself. I found other landing challenges requiring fairly advanced piloting skills to acheive required score, however I took about 7-8 attempts to get an A score on a few occasions for other challenges.
Analysing further on the runway pattern, landing zone and other things, I have listed some interesting points which I think other experienced pilots might have also noticed and would agree with me on the same.
Hoping our brilliant MS Devs can fix these issues asap and put a smile on every pilots face 
- The landing zone (cyan square box) on the runway is awkwardly positioned to the right instead of center.
This has 2 downsides a) It teaches a good pilot to pickup some bad habits along this kind of learning curve. For e.g. to perform touchdowns at the edge of the runway or sideways instead of aiming for the centerline whilst fighting against strong winds, this can prove dangerous if attempted in real life. b) By placing the landing zone in the right, you are actually creating a risk of pushing the aircraft even more to your right during unpredictable wind conditions and your aircraft is more likely to land in a pond and not on the designated runway!
- Ground Roll: How are we calculating ground roll on a short curved runway like this? What are the expectations for this level? Why there are no hints or dotted lines on the runway to indicate or assist the pilot with ground roll deviation when there is a curved runway?
Consider these 2 scenarios below, I think eitherway you are going to lose points in this.
a. If the pilot is aiming for the centerline regardless of the wrongly positioned landing zone, then this will cause deviation from their path (shifting from right towards the center). System is going to treat this is as a bad ground roll and reduce their score which is unfair.
b. If the pilot is aiming to go along the right side of the runway soon after correct touchdown on the landing zone, which is also positioned on right in this case, this will end up having aircraft parked on the right side of the runway but not in the center. The system is going to treat this as deviation from center line.
Again this is a different logic that is not followed in all other challenges, why?