I think I figured it out, but for real this time.
Anna played with 4 different people.
I'll get to the explaining after I eat dinner.
As has already been established, Jason received 9 different answers, and those answers were 8,7,6,5,4,3,2,1, and 0.
For it to be possible for both 8 and 0 to have been given as answers, the person who played with 8 different people must have been married to the person who played with 0. i.e. No one played with themselves or their partner, so if someone played with 8 different people, each of the people they played with played at least that one game.
Thus 8 and 0 are paired, which means Anna is neither, because Jason isn't answering.
Holding to the same logic, the person who played with 7 other people played with everyone except their partner and the person who played with no one, forcing all remaining party goers to have played with at least 2 different people. Therefore, the person who played 7 other people must be married to the person who played with only 1.
...6 and 2 are paired
...5 and 3 are paired
And 4 is left unpaired, so it must be Anna.
We have a winner! PM me your address and shirt size to claim your prize.
Reasoned slightly more thoroughly:
Because, obviously, no person played Donkey Kong with himself or herself, or with his or her spouse, nobody played Donkey Kong with more than eight other people. And since nine people played Donkey Kong with different numbers of people, these numbers must be 0, 1, 2, 3, 4, 5, 6, 7, and 8. We will refer to the people that gave those answers correspondingly as Person 0, Person 1, ... , and Person 8 respectively.
Person 8 played Donkey Kong with everyone except with his/her spouse. Therefore everyone at the party except for Person 8's spouse played Donkey Kong with at least one person. Therefore, the spouse of Person 8 must be Person 0.
Person 7 played Donkey Kong with everyone except his/her spouse and Person 0. Therefore everyone at the party except Person 0 and Person 7's spouse played Donkey Kong with at least 2 people (Person 7 and Person 8 ). Therefore, the spouse of Person 7 must be Person 1.
Person 6 played Donkey Kong with everyone except his/her spouse and Person 0 and Person 1. Therefore everyone at the party except Person 0, Person 1, and Person 6's spouse played Donkey Kong with at least 3 people (Person 6, Person 7, and Person 8 ). Therefore the spouse of Person 6 must be Person 2.
Person 5 played Donkey Kong with everyone except his/her spouse, Person 0, Person 1, and Person 2. Therefore everyone at the party except Person 0, Person 1, Person 2, and Person 5's spouse played Donkey Kong with at least 4 people. Therefore the spouse of Person 5 must be Person 3.
The only person left that answered Jason is Person 4, which must be Jason’s wife, Anna. The answer is: Anna played Donkey Kong with 4 people.
The chart below shows the scenario. The married couples are denoted by grey-shaded ovals. The colored lines connect the people who played Donkey Kong with each other.
