The story: your life as an eight-year-old is enlivened by, why not, aliens landing in your backyard, except that these aliens clearly have been reading Calvin and Hobbes, since they're invisible to your parents. They commission you to run some errands for them so that they can get on with enslaving the planet, so you carry out some tasks, of varying degrees of silliness, to Thwart the Evil Plan.
The author titles Arrival an "attack of the B-movie cliches," but that isn't really fair: Arrival is far wittier than any B-movie, and it's far too self-aware to be cliched. (Your character's reaction upon seeing the spaceship: "Oh man oh man, it must be a spaceship! From outer space! Maybe from Gamma Proxima Epsilon Centauri Five B!") The aliens owe much more to parody than to cliche: they demand Ho-Hos and grumble about the obnoxious way Earth constantly sends banal radio broadcasts into space. On hand is a translator that mutates the aliens' speech into Bill and Ted-speak, with consistently amusing results (the answer to one question changes from "You are quite a nosy child" to "Why don't you, like, go play in traffic"). The fact of the alien-invasion plot should not obscure the amount of wit that went into the writing of Arrival: for instance, when the alien's translator fails, he scowls and yells "Universal translator, my anterior appendage!" Few games can claim the amount of originality that Arrival offers.
The fun of the game is largely in the writing and the amusing asides, however, rather than the puzzles: some are clever, but a few are simply obscure or insufficiently clued. There's a hint file to help things along, and Arrival is the rare game where it's better to turn to hints than to insist on unraveling puzzles yourself. The fun of the game diminishes when the player is stuck, and the payoff associated with solving the puzzles isn't so great that resorting to hints takes away a sense of accomplishment. The charm of Arrival lies, in short, more in seeing the aliens' funny responses to different actions than in solving problems, and it is hence more rewarding to move the story along, in order to discover more parts of the game that produce funny responses, than to stand still until you solve a puzzle by your own wits. The puzzles aren't especially bad or unfair, to be sure, but by and large (with one exception, a puzzle that turns on a sly joke about child-proof lids), but they don't match the level of the writing either.
If there is a flaw in Arrival, apart from the puzzles, it is that your identity, an eight-year-old, only surfaces intermittently. There's plenty of humor to be mined from the world as viewed by a child--Calvin and Hobbes, for one, produced about ten years' worth. Aside from the occasional response, though (TAKE STICK when no stick is present: "I don't see no--I mean any--stick here"), you can largely forget that you're eight years old--and there are several moments, such as the discovery of a velvet Elvis and a rain stick, that might be enlivened by commentary from an eight-year-old's viewpoint. (On the other hand, your eight-year-old self comes out more clearly in some of the AMUSING responses, suggesting that the author wanted to mine that vein of humor but didn't get around to incorporating it into the story much. Moreover, as I understand it, the graphics appear to have been drawn by an eight-year-old, so perhaps that changes the game experience for those who can actually see the graphics.) It's a minor flaw, though, and testifies to the general solidity of the game and its coding.
Arrival is a well-crafted game--at least, the text portions are, and I trust the graphics and sound add to the experience. It's also littered with in-jokes and funny asides that more than make up for the derivative nature of the plot, and it plays up the alien invasion for satiric value, which excuses the cliches (for me at least). Reminiscent in some ways of Carl Klutzke's Poor Zefron's Almanac, but much more consistently funny and playable, Arrival is a worthy effort.