YMMV / Dr. Brain

• Game-Breaker: In Time Warp, you can exploit viruses in the otherwise very difficult Genius level of Primordial soup to gain easy wins ^Note  The way viruses work is by infected a cell when they touch it, causing them to decay much faster and explode, which creates more viruses. Y'know, kind like how real viruses work.. So either you could wage an epic battle against the incredible competent enemy cells, or you could infect one of your cells, send it into enemy territory, let it die and watch as the enemy slowly but surely die out as the virus spreads throughout their battalion in a hopeless war while you watch from a safe distance, you monster.
• Narm: Elaina's voice-acting in The Lost Mind of Dr. Brain. Eliana, would it kill you to at least sound a little interested in helping your uncle recover his lost marbles? What's especially bizarre about Elaina's voice-acting is that she does show genuine emotion in the game's opening and ending cutscenes, yet has an uninterested-sounding monotone voice for the better part of the game. Maybe it had something to do with how her uncle wouldn't listen to her and stop the experiment on his own, and when she tried to stop him herself, she was already too late.
  "We should continue reconstruction imEEEdiately."
• Surprise Difficulty: Some puzzles are a lot harder than you expect when you turn up the difficulty.
• That One Level: There's going to be at least one puzzle in each game you'll decide you hate. Most likely the one which targets your weakest area.