Quantic Foundry is a company that's made it its business to understand and quantify gamer motivations. To that end, it's collected detailed information on more than 140,000 gamers, identifying their favorite games and what makes those titles most attractive. The output of that research is multifaceted, but perhaps the most interesting part of it has been the below chart identifying the relative cognitive burden that each game asks for.
Grand strategy titles like Civilization and Europa Universalis require more "thinking, planning ahead, and making decisions," whereas Counter-Strike is a good example of a game that throws up "fast-paced action and gameplay that rewards rapid reactions." That much is intuitively obvious, however plotting all these various games against one another gives a sense of the proportional difference between them. And it also illustrates the challenge and demands inherent in each game: Football Manager moves at a languid pace, and even though few would argue it's an easy game, it falls into the "easy fun" category here because it doesn't make any great impositions on the player. Dota 2, on the other hand, mixes fast reaction requirements and complexity to the very edge of being too difficult and demanding to be fun.
Dota 2 is almost too hard to be fun
"There’s a cognitive threshold beyond which forcing you to make complex decisions under time pressure is simply not fun anymore," says Quantic. The company hopes its data will prove attractive to game designers eager to position their titles appropriately on this excitement / strategy matrix, though there doesn't appear to be a clearly superior approach. The most addictive and popular games show up in every category, with the heroin-like Hearthstone sitting close to the middle.