Forced to watch ads or given rewards for watching ads.
"This game has advertisements that you can watch for in game rewards, provided by a mechanic called "Monsterwood" which is a parody of Hollywood. In addition, if you have yet to pay for the game, intrusive ads appear randomly."
"There are ads in this game, you can watch them as a reward to keep going, if you say no you watch one anyway with no reward. You have to spend real money for there to be no ads. You can also watch an ad to get a free resurrection"