straight poker vs poker game

straight poker and poker game both are nouns.

Word	Noun	Adjective	Verb	Adverb
straight poker	Yes	No	No	No
poker game	Yes	No	No	No

As nouns, poker game is a hypernym of straight poker; that is, poker game is a word with a broader meaning than straight poker:

straight poker: poker in which each player gets 5 cards face down and bets are made without drawing any further cards
poker game: any of various card games in which players bet that they hold the highest-ranking hand

Other hypernyms of straight poker include poker.

straight poker (noun)	poker game (noun)
poker in which each player gets 5 cards face down and bets are made without drawing any further cards	any of various card games in which players bet that they hold the highest-ranking hand