There are a variety of different types of games on the market, and virtually all of them fit into one niche or another. Some people just really prefer their sports games, others have a taste for the storytelling that RPGs afford, and some people just want to blow stuff up. There are people whose interests will span the genres, of course, but there’s really only one genre that tends to have near-universal appeal: puzzle games.

That doesn’t mean that every puzzle game will appeal to every gamer, of course, but the genre as a whole does attract gamers from nearly every demographic. Heck, Nintendo’s Game Boy phenomenon is what it is because of perhaps the most successful puzzle game of all time: Tetris.

Puzzle games are, by nature, simple and easy to get the hang of; that’s part of what makes them appealing to such a large crowd. Mom and Dad can pick up such games, because they don’t require great feats of mental contortionism to get the hang of playing them. Kids get into such games because they have the ‘hot’ gameplay that companies always used to look for in arcade titles: that is, they grab you within the first few seconds.

Given that they’re inexpensive to produce, easy to design, and easy to pick up and play, it’s small wonder that puzzle games frequently see the light of day early in a game system’s lifespan. We saw Chu Chu Rocket as a launch title for both the Dreamcast and Game Boy Advance, and Mr. Driller on both the Dreamcast and the fledgling Nintendo DS. In addition to Mr. Driller, two months after the launch of the DS, there’s a second puzzle game on the market: Zoo Keeper.

Another characteristic frequently seen in puzzle games is that of derivation. Sega’s Columns was little more than a derivative Tetris, asking you to cycle through colored jewels to eliminate vertical or horizontal lines of three blocks or greater. In the same way, Zoo Keeper is derivative of Bejeweled, although both of those games are I turn derivative of Columns, which is…well, you get the picture.

Zoo Keeper isn’t exactly the same as Bejeweled, but if you’ve played the latter, you’ll have absolutely no difficulty with the former. The root gameplay is the same, while externally there are three differences between the two games. The primary, most evident difference is the fact that Zoo Keeper introduces animals in place of jewels.

The premise places you in the role of a zookeeper (imagine that!), whose job it is to keep order among the animals. Order is kept by lining up three to five of the same animal, at which point they disappear from the playing field, allowing more animals to fall down. As I said, it’s the same principle you’re already used to. To advance to the next level, you need to clear a specified number of each species of animal. As you advance through the levels, the number of animals you need to clear increases, as do the number of species needing clearance.

Zoo Keeper also has something of a story mode. It’s not going to set the world on fire, but it is good for the occasional laugh, and it lends itself to some variations on the gameplay, as well. Quest Mode, for example, has your character interacting with the balding, ranting gentleman who runs the zoo. He’ll give you ten tasks – they’re the same every time you play, unfortunately – and he grants or deducts points based on how you complete each task. Speed counts, as does your ability to complete the task with a minimum of external fuss. If you do well, he’ll give you some random sentiment of praise (“samurai-like mercy!”) and grant you either a straight point value, or a percentage increase on top of your existing point total. Failure results in comic beration, and a percentage reduction of said points.

The Tokoton 100 mode is essentially the same as the basic gameplay mode, except that advancement comes after you clear 100 of any species on the board. Otherwise, the same principles hold true: you have a timer, which steadily counts down, but which you can increase by clearing animals and chaining together combos. If you run out of moves, you earn a time bonus, and a new playing field as well. You can earn sets of binoculars as you play, giving you a peek at where a possible move might be if you get stuck. And, as with all of the gameplay modes, when the timer is nearing completion, the screen will start to shake to warn you that the end is nigh.

There’s also a time attack mode, which gives you either six minutes, or until your timer bar runs out – whichever comes first – to score as many points as you can. Once you’ve exhausted the single player modes, you can also link up wirelessly with a buddy – even if only one of you has the game – and play a multiplayer game where you can decrease your opponent’s timer bar by stringing together combos.

No matter which mini-game you play, you have the option of using either the D-pad and A button, or the touchscreen stylus. Either way works just fine, but generally speaking, the game seems better suited to the stylus, a fact which hopefully portends well for future puzzle games on the DS. I do recommend, however, a sort of hybrid play; the L trigger will use the binoculars just the same as if you tapped one of the binocular icons on the touchscreen, and using that when you need a hint leaves you free to leave the stylus poised over the board, particularly when time is running low and you need a miracle.

Visually, Zoo Keeper isn’t spectacular, but it doesn’t have to be; it is, after all, a puzzle game. The top screen shows your score above a stylish rendering of the current “lucky” animal (which grants you double points every time you remove a set of that animal from the board), and the lower screen shows the board. The game is also brightly colored, which is nice - particularly if you’ve ever played, say, Castlevania on an original GBA. The built-in light is wonderfully useful, of course, but even if the light weren’t there, being able to see the game is a good thing.

The music is likewise bright and catchy, but it won’t invade your consciousness and take up permanent residence therein the way Korobeiniki (the Russian folk song, which later was used as original Tetris theme) did. Still, I find that Zoo Keeper is more enjoyable with the volume turned up than turned down, and that’s always a positive thing.

In the end, it boils down to how hard up you are for some puzzle lovin’ on your DS. Zoo Keeper is certainly enjoyable, and addictive as well, and that alone is enough to recommend it. The $39.99 price tag seems a little steep, however, which may scare some off. If you find yourself in that group, don’t let yourself miss it – just watch for a sale or a price drop before you pick it up, that’s all.