And that's before you get to the buggers with the granite headwear. You could, I suppose, admit the game is fairly realistic in that respect - catapult a bird at a sheet of ice or a slab of concrete at high speed and it's not hard to guess which is going to come off worse.
All of which would be fine, except it's impossible to determine that perfect shot. Getting it right is simply a matter of perseverance and educated guesswork: you plug away and plug away until all the pigs are destroyed and you can move on.
With no way of knowing the trajectory or power of your last shot, you poke lazily and impotently at the screen, trying to locate the exact point of release the game requires you to find.
It's like being asked to hit a bullseye in darts, only the dart is replaced by a cocktail sausage with a pin in the end, the oche is 50 feet away from the board, the board is made from blancmange and you have to throw with your feet. In the dark. In a wind tunnel. On Mars.
But the rewards for completing such a Sisyphean task are worth the effort, right? Not a chance. You get a few half-hearted whoops from the remaining birds, a silly little jingle plays, and you're given a grade between one and three stars.
Yet the scoring system seems to be governed by an arcane set of rules which probably not even the developer can entirely fathom. Wipe out all pigs with a couple of perfectly-aimed launches and you might get a piffling single star. Bludgeon your way through with a flukey final fling that somehow dislodges that tiny piece of wood above the one remaining pig? Three stars.
I've played stages over and over, trying to figure out exactly how it works, and the scientific conclusion I finally arrived at is this: the game simply makes it up.
So, it's random. Random games can be fun. But most games with a hefty element of luck at their core at least attempt to deflect the player's attention away from the fact.
Take Popcap's equally moreish Peggle, for example. It has a far superior setup to Angry Birds, at least affording you the illusion of fine control to guide your shot, even if its eventual trajectory is nigh-on impossible to predict.
But even if it didn't, it'd still have the slo-mo zoom on that final peg, the thunderous drum roll, those fireworks and that stirring rendition of Beethoven's Ode To Joy to celebrate successful completion of a level.
Angry Birds has none of that. There are no audiovisual pyrotechnics, no fanfares, just a shrug and an arbitrary score and you're back to the level select screen. "You won?" it says. "Meh. Keep playing, sucker."
It's not as if its visual identity is particularly strong. The birds themselves have become icons simply through ubiquity; they're not characters, just units of ammunition of different shapes and colours who happen to share a similarly narked-off expression.
Otherwise you're playing an entirely ordinary Flash game, the kind of throwaway nonsense you would usually waste ten minutes of your lunch break on and then completely forget you'd ever played.
It's barely even a game, more a modern executive toy to give your thumbs something to do when you're feeling particularly bored and feeble and bleh. Because there's barely any skill involved, there's no satisfaction to repeating the same mundane actions.