and suddenly thinking of that both Game and Gaming are NOUN.
If all words (including Nouns and Verbs) plus "-ing" can be a NOUN?
No, any word plus -ing is NOT necessarily a noun.
A verb in the progressive aspect has -ING: "I'm talking."
A verb as a gerund uses -ing: "She likes hiking."
A lot of adjectives are derived from progressive participles:
"This problem is very interesting ."
"She's more interesting than her sister."