This PewDiePie guy doesn’t look good.
https://kotaku.com/indie-dev-calls-for-copyright-strikes-against-pewdiepie-1803099736
I listened to a podcast on the topic of DMCA’ing Let’s Plays.
https://headgum.com/robot-congress/robot-congress-46-pewdiepies-dmca-dilemma
Apparently Campo Santo is definitely legally within their rights to DMCA any and all Let’s Play content of their games, given that the “license” on the FAQ page of their website is (by default under the law) revocable at any time to any individual, and the work is not original but derivative. However, Campo Santo would not be able to sue PewDiePie for the money he already previously made under said license.