You wouldn't think there would be a lot of variation possible on the Tetris theme.  And you'd be right.  But Alexey Pajitnov, the creator of the game that took the world by storm, has been surprisingly innovative with his signature line of puzzle games for Spectrum HoloByte.  There's not much that Breakthru has in common with Clockwerx, for example.  The only thing these games (and the other products in the line) have in common is that they're completely abstract and quite addictive, like their spiritual parent, Tetris.

	The latest game in the series is called Qwirks, and while it's not at all far removed from the game that started it all, there are some unusual subtleties.  As in the original Tetris, there are colored pieces that drop from the top to the bottom of a pit, and the player can rotate the pieces at will before they land.  But the pieces are actually two "qwirks" (little jelly-like blobs with eyeballs) of different colors joined together for their descent.  If one half lands on an uneven bit of foundation, leaving the other half dangling, the exposed part falls off to sit on the lower level. 

	Removing qwirks from the pit follows slightly different rules than you might expect.  Any four or more qwirks that are touching each other, either horizontally or vertically, are zapped away.  If you're playing in competition with one of the 13 computer opponents or with a human, it is definitely to your advantage to set up some cascading patterns.  In other words, instead of just eliminating every four-of-a-kind that pops up, you should arrange the qwirks so that the removal of one set will lead to the removal of another just by the effects of gravity.  When this happens, your opponent is saddled with a horizontal row (or more) of transparent qwirks!  These guys look like soap bubbles with eyes, and they won't pop unless they are right next to a disappearing set.

	This strategic element takes some practice to master.  Thankfully, the designers set up two ways to prepare for the kind of cutthroat competition this game leads to.  The "practice" mode is just a one-pit setup that goes faster and faster until your screen fills up.  There are two "domesticated" qwirks who pop up to help when things get out of hand.  One of these strange allies goes through your board randomly, changing all the qwirks it touches to the same color, which can make things a lot easier.  The other practice helper is a bloated qwirk that takes up two columns.  When it drops straight down, it erases whatever is in its way, leaving two clear columns.

	You can also improve your strategic planning by playing the puzzle mode.  A pattern of qwirks is set up, with a series of qwirk-pairs in line, waiting to drop.  The challenge is to use the qwirk-pairs as they drop to completely eliminate the pattern.  This starts out easy, but can get very convoluted, sometimes causing as many as six-part cascades to occur. There's no scoring here -- it's pass or fail, and if even one qwirk is left over, you failed.

	As mentioned above, there are thirteen different AI opponents, each with a distinctive playing style.  The characters are represented by a nicely animated creature in the center of the screen.  These range from insects to apes to fish to indescribable mutant things, and they actually react to the game as it takes place.  If the player is doing badly, the figure gets more and more giddy, and may eventually wag its tail or clap its hands when it wins.  On the other hand, if the adversary's pit starts really filling up, the figure gets frantic and flustered, finally collapsing in shame at the player's victory.  This is really satisfying to watch.

	The sleek animated style also extends to the colorful playing pieces themselves.  The gelatinous quirks jiggle and jostle all over the place, their eyeballs move to check out their new neighbors in the pit, and just before they disappear, their eyes go wide with surprise.  It's just adorable.

	While Qwirks isn't quite the gameplay innovation that Clockwerx was, there's no denying its appeal.  It's like a cross between Dr. Mario and a Duckman episode.  This is no replacement for the original Tetris, one of the few video or computer games that can be called a classic without a snicker.  But if you're looking for an amusing twist on a familiar theme, Qwirks would make a good addition to your library. For that matter, so would any of the Pajitnov line -- there hasn't been a clinker in the bunch yet.