I've listened the pronunciation of the word "hangover" on Cambridge dictionary, both UK and US.
I am aware that the g is pronounced as /ŋ/ here and I really didn't catch the phonetic sound "g"[g] in there.
Nevertheless, I actually heard a few of people pronounce "g"a [g] in "hangover", like (like the "g"[g] in "game").
So, should "g"[g] in "hangover" be pronounced or silent?
Here is an example of a Canadian accent.