A long-standing web game classic is given new life on the PSP, and oddly enough it feels more at home on Sony’s handheld then it does on the internet. Still, is Vector TD worth the money when you can play the Flash version online for free?

The answer, of course, is a resounding “yes!” The kind of “yes!” that makes the ears bleed. Vector TD is one of the classiest Tower Defense games around and, like most good games in the genre, is addictive as all hell. The asking price of $3.99 is totally worth having it on-the-go and it’s a steal when you consider how many hours you’re sure to sink into it.

Vector TD doesn’t mess with what works, keeping things ultra-familiar and straightforward. In fact, simplicity is the running theme here. The mechanics, the aesthetics; all of it is boiled down to its most rudimentary form. But just because it reeks of simplicity does by no means make it simple. Vector TD is one of the more challenging Tower Defense games available and is sure to stop you cold at some point, forcing you to dig deep in order to come out on top. That is, if you can even do it.

The tower selection is limited to four types, with each type offering up to three tiers of effectiveness. These towers are the staple kinds in the genre: Splash, slowdown, quickness, and raw power. The game adheres to the most basic, established principles of Tower Defense, including enemy types. Vector TD is no worse for it.

Despite Vector TD’s overall awesomeness, there are a couple issues that some players may take umbrage with. The graphics are nothing more than clever line arrangements. The game gets insanely tricky on the advanced maps, verging on impossible. And the fast-forward feature commonly found in these types of games is noticeably absent here. Ripping through 50 waves of enemies can certainly eat some clock because of this, but chances are you won’t notice because that’s the nature of addictive things.

Vector TD is highly recommended for anyone, whether they are a Tower Defense enthusiast or a gamer who just likes enduring replayability. It’s a great addition to the library of PSP Minis, and one of the easiest ways ever to kill an entire afternoon.