If that game is not based on an actual event, I'd like to try it.
I wouldn't mind playing that game as long as I know it's not based on a true story.
この場合、次のような言い方ができますよ。
ーIf that game is not based on an actual event, I'd like to try it.
「そのゲームが実際の出来事を基にしていないなら、やってみたい」
ーI wouldn't mind playing that game as long as I know it's not based on a true story.
「そのゲームが真実を基にしていないなら、プレーしてみたい」
ご参考まで!