It is interesting question. I did not yet think deeply. But I thought about feature elements necessary to realize this. I want you to read as reference information.
Display of user profile:
Feature below may be useful.
Admin > Users > "User titles based on points" > "Add new title"
e.g.: "Title"="5000 points holder", "Points required to receive title"="5000"
Gift stats (flag) of users:
Feature below may be useful.
Admin > Users > "Extra fields on user pages or registration form" > "Add new field"
e.g.:
"Field name"="5000 points gift stats", "Content type"="Single line", "Visible for"="Administrator", "Show field on user registration form"="OFF"
"Field name"="10000 points gift stats", "Content type"="Single line", "Visible for"="Administrator", "Show field on user registration form"="OFF"
Useful hack for checkbox : Extra Userfield
Other issue:
How does admin know that users arrived 5000 points?
Useful plugin for searching user : User Search Pro
In addition, I may add a new feature in NP to notify admin that users arrived at the specific point.
Thanks.