See, Alfonso Sr. -- decked out in familiar plumber's garb and inexplicably sporting a cockney-esque accent not far removed from Michael Cane's turn as Alfred in the new Batman movies -- is apparently good at his job (good enough to buy himself his own island, anyway). He wants to hand the bidnizz off to his kids, though, which is a problem because of what he calls "Cowboy Plumbers," one of which is particularly bad, so he sends the kids off to tackle the island's resident "bad guys" first to give them some experience.
Okay, so it's not much of a story -- really just there to lend context to a bunch of characters and their resulting special attacks (which I'll get to in a second), and to give the game a reason for having a bunch of different environments like a train yard and internet facilities, but they're honestly just different skins for the main gameplay; the pieces are more or less the same (though the game does do a good job of constantly introducing new mechanics), which is to say you'll be spending plenty of time building snaking lines all over the gridded levels, trying to build faster than the slime (sorry, Flooze) can flow through the pipes.
Though it's rather fleeting, Pipe Mania does offer a bit of a cushion after the Flooze busts out of a pipe. A leak meter will fill quickly when the Flooze isn't being directed somewhere, but at least the game isn't over as soon as soon as the green slime, or stuff on conveyor belts or little trains fall off the main path. Ah, but there's a catch, and one that becomes increasingly persistent as you roll into the boss battles with the other plumbers at the end of each area: they can break the pipes with special attacks, which cause leaks that have to be repaired.
These boss battles, as the game goes on, start to get more frustrating than anything else, especially when moves like being able to switch out or rotate pieces starts to crop up in addition to just causing leaks. Granted, they certainly do introduce a little more variety into things, but it's rarely welcome when the latter stages start introducing things like forced routes or even splitting the Flooze in multiple directions. It was clearly meant to be a multiplayer option (which the DS version lacks, along with about 50 levels found on the other platforms), and there it certainly complicates things, but in single-player it really just adds frustration.
Pipe Mania can be a rather difficult game, and that's before you factor in the added challenge of racking up points for medals (which in turn can give you treasures that unlock more levels and modes). All the basics are as you'd expect; tapping a shoulder button (or holding the right mouse button on the PC) speeds the flow up, cross pieces loop Flooze and let you pocket more points, bridges can turn normally straight pieces into crosses, gates speed up/slow down the flow and the aforementioned splitters and colored gates require an extra bit of clever building.
The pieces, however, seem to be randomly chosen, which I can understand would be done to build tension when you're trying to beat the flow and are just waiting for one piece, but because you can't skip a piece and must put it down somewhere (even on top of others), you'll either incur a penalty at the end of the level if you can't link the piece or you're get dinged instantly when you bust through a previous piece. When things get seriously twisted later in the game, it only gets worse.
There were also moves taken to make the levels themselves more complex; pre-set pieces can't be bombed or changed, obstacles must be built around and bonus pieces give you more points if you can incorporate them into the run. Each of these compounds the earlier issue of just having to burn through some pieces, and though it's certainly more involved than the old Pipe Dream formula, it's also needlessly complicated at times.
With the exception of some of the stuff I talked about before, all versions of the game are essentially identical. The PC version runs just fine on integrated graphics chipsets and obviously has low requirements there, the DS version, like the PC with its mouse, benefits most from not having to scoot around the levels one square at a time, but lacks levels and multiplayer. The PS2/PSP versions are all but identical, and run just fine. In short, the core experience is the same across all platforms, but the DS version is a little short-changed.