Redon said:
The similarity with Popeye is really good since one of the things the "awakening" gives to Luffy is "freedom". And that "freedom" allows Luffy to fight as he wants and in this case(for now) he is fighting like if he was from a cartoon with all crazy type of things.
And as you see it doesn't affect only him, it affects to his enemies too(that's why Kaidou looks like he was taken from the Looney Tunes)