In this day and age, most third-party games are released across multiple platforms. When the game in question is a major licensed property, like Spider-Man 2, it's almost guaranteed that you're going to get the same game on several different systems. Activision did this, in part, by releasing a Treyarch-developed Spider-Man 2 game on the Xbox, PlayStation 2, and GameCube. But for some reason that game didn't make its way to the PC. Instead, PC owners are getting a completely different game. Between the game's overly simplified gameplay mechanics and its weak presentation, this is definitely a case where "different" doesn't mean "better."
At its core, the PC version of Spider-Man 2 is attempting to do the same thing that the console game does. It takes only the most basic shreds of story from the movie of the same name and inserts them into an action game. In an attempt to liven things up a bit, the game does more than merely pit Spider-Man against Dr. Octopus. You'll also face other villains, like Mysterio, the Puma, and on multiple occasions you'll square off against Rhino. When you aren't doing that, you're stopping bank robberies and beating up on other, lesser thugs. Generally speaking, the game doesn't go out of its way to tell any story at all. You'll get a cutscene here and there, but most of these cutscenes are ugly. A few of them come from the console versions of the game, and these look just fine. But the cutscenes that were created specifically for this version of the game are awful. They run at a choppy frame rate, and the scenes would probably look better if they were just rendered in-engine.
The gameplay in Spider-Man 2 is stripped-down to a fault. The game controls like your standard third-person PC action game, with the mouse controlling your turning and viewpoint and the keyboard controlling your actual movement. The left mouse button is a context-sensitive, all-purpose action button. If you're pointing your targeting crosshairs at an enemy, an onscreen targeting device will say "attack" or "web" if you aren't close enough to punch. Pointing at the side of a building or other flat surface will let you "zip" to that location with a touch of the button. In some cases, you'll be able to "shoot" web balls at various targets. And when you're close enough to a swing icon, your targeting device will light up and say "swing."
Wait, a swing icon? Yes, that's right. Unlike in the other version of Spider-Man 2, where you can swing around the city freely, here you can swing only from specified swing targets. This, in a word, is lame. In two words, it's incredibly lame. The freedom of swinging around the city is one of the standout features of the other version of the game. Here, it's just a joke, whether you've seen the other version of the game or not.
The boss fights in the game are, for the most part, dumb. It certainly doesn't help that the game pauses before each fight and spells out exactly what you need to do to win before every single fight. This feature and the one-button gameplay may have you thinking that the game was intended for kids, but the game is really ill-designed all over the place, and it doesn't feel like it's catering to any specific crowd. It's also a fairly short game, clocking in around the five- or six-hour mark.
Graphically, Spider-Man 2 looks OK. Most of the game takes place in a city environment, but the rigid, boxlike structure of the skyscrapers doesn't make you feel as though you have any sort of citylike freedom. The game's textures are passable, though most of the non-player models are ugly and animate poorly. When you beat enemies, they blink out of existence with a static effect that makes you feel as if you're playing some sort of "Spider-Man in The Matrix" mod. The whole game just looks dull and unexciting, both technically and artistically.
Most of the sound effects in the game are good, but this is offset by some bad voice acting. You'll hear some of the voices from the movie here, but Tobey Maguire must have used up all his voice-acting energy on lines for the console version of the game. Here, the script is bad to begin with, and the line delivery isn't any better. The game has some music, but it basically just fades into the background and stays there.
Why didn't the PC get the good version of Spider-Man 2? Who decided to make an entirely different and decidedly mediocre version of the game specifically for Windows users? We may never know the answers to these questions, but as for your question about whether or not you should spend your time and money playing this version of the game, the answer is definitely no.