Simplicity = fun If you like to think, don't think aboout it; buy it
Polarium has two main game modes. The first one is Challenge Mode, in which you're asked to clear as many lines as possible, while more and more pieces of tiles stack up in the lower screen; if you get too many stacked up, it's game over. This mode is the fast-reflexes one, where you need to look and think ahead of the game to get more lines cleared. Very fast pased and a little bit addictive, but just a little bit. Is it fun? Yeah, but it gets old fast, and repetitive.
Puzzle mode is my personal favorite. There are 100 puzzles in which time is not your enemy but your friend. You're given unlimited time to look at a series of tiles and think and ponder 'Hmmm...how can I trace a single stylus stroke throughout the touch screen to make all the lines dissapear?" That's basically it. Sounds simple? It is, but it is very fun and addictive too. WARNING - You will only like this mode if you like to take your time and think; if you expect to find the answer right away, this mode is not for you. The harder puzzles are at the end, and boy are they challening; you'll spend a good amount of time clearing these 100 puzzles.
Polarium also features a puzzle-save function. You can either enter puzzle codes you get online or from freinds, or link your games; doing either of these gets you more puzzles to solve. And you can make your own too.
There's also a VS mode where you turn your DS to the side and try to clear as many lines as possible. Lines you clear are sent to your opponent, and whoever gets a clear screen first, wins the match. Kinda fun, but not a whole lot.
Many, many people bash and trash-talk this game because of the graphics. Granted, they aren't pretty, but this is a puzzle game; it doesn't need pretty looks to be fun. The sound is also a little shallow though, and puzzle games do need good sound to keep the fun gameplay company, so that's a low point.
Replay value? Well, if you want to take the time to enter those long puzzle passwords, you could have some fun searching for puzzles online. Otherwise, once you beat Puzzle mode and get some good scores in Challenge mode, the game is pretty much over. VS Mode doesn't do much either.
A good game that could've been better with some extra modes or options. Worth buying? Pretty much, especially since you can find it for $10 at some stores. Give it a try!