Why casual games are addictive: an unordered list.
No instruction necessary: learn as you play; the game won’t eat you alive if you don’t know what you’re doing.
You only need one hand: you can play casual games while riding the subway, or eating a sandwich. Simple controls also make them less intimidating to newcomers.
You’re not gonna die if the phone rings: a lot of the action is dependent upon the player, so if you need to walk away for a minute you’re not jeopardizing hours of gameplay. Plus…
If you lose, it’s not the end of the world: casual games don’t penalize you too hard for failure; there’s little to no chastising for making a mistake, and innumerable opportunities to retry a level. No ominous ‘game over’ screens here.
The simplest actions become significant: Match two diamonds and fireworks go off. Spell a word and it makes a fireball. Nothing keeps a player going like the satisfaction of accomplishment; they’re playing for the bells and whistles.
You can play for five minutes: …but you never do; “Just one more round…”