Draw a line. OK, you'll have to give it a bit more thought than that as you won't be passing through all the squares on screen, but Polarium Advance is a simple game to play. Each puzzle consists of white and black tiles and once you've picked a start point you must draw a single line, moving around the screen flipping any tile your line crosses to show the other colour. Rows that are completely one colour disappear and you must make all rows disappear to complete the puzzle. The gameplay may be simple, but the puzzles can get tough.

The controls feel very natural with the d-pad or control stick moving a cursor around the screen. When you are ready to draw your line you simply tap the A (or L) button, and once you've finished you tap it again to flip the selected tiles and hopefully clear the puzzle. If you've made a mistake drawing your line you can simply backup, retracing your movements before snaking off in a new direction. If you think you've made a complete mess of things a push of the B button will erase your line and you can start again. Some of the bigger puzzles are shown zoomed out in order to fit the whole thing onscreen, but pressing R will zoom in for a better look. It's not really needed, however, as the tiles are still visible (although smaller), particularly if you're viewing the action on your television. The controls work well, but as always you can indulge in some button remapping via the Virtual Console options if you so wish.

The main mode of play is "Daily Polarium". When you first begin you set the date and then the game gives you a puzzle every day for a year. It seems the game has been set up for short play, something to do after your daily Brain Training or something for people who also do a single sudoku or picross puzzle each day. This could potentially be annoying, but thankfully they are not date-locked and you can do as many or as few as you like. Only a few puzzles are available initially, but more unlock as you clear them.

There are a few sketches in the background throughout, but as a puzzle game involving black and white squares it has an unsurprisingly simple appearance. Developer Mitchell Corporation added some simple but effective touches, however, such as the way your cursor spins when idle and pulses when you've drawn a line, whilst rows disappear in a satisfying pyrotechnic display. If you are fed up of looking at black and white squares there is an options menu where you can select different colours for the tiles and the cursor. Sound effects consist of simple taps, clicks and bloops whilst the music during play is a variety of chilled out tracks that generally works well, but mostly goes unnoticed. There are some other tracks on menus that are a bit more adventurous; they may whine a little but, ultimately, you won't be listening to them much. If either the effects or the music are irritating you they can be turned off in the options menu.

The initial puzzles are very easy, but things soon get tougher, requiring some extra thought. Puzzles have grey border tiles that will not change when your line goes over them, but after a while you will find some of the border taken up with blue crossed tiles that you cannot pass through. "Multi-tiles" actually look like areas in a public toilet where, due to vandalism or a lack of maintenance budget, tiles have been removed from the floor. In any case, these (like border tiles) can be passed over by your line without effect, but will change to a coloured tile if the rest of the row matches. The final type of tile is one that once you've made the row match colour, causes the tiles above to drop below. The introduction of these special tiles gives you new things to consider when trying to figure out the solution.

Figuring out the solution to a puzzle can take some doing as they are not all handled the same way; some will require you to turn all the tiles one colour whilst others will see a mix of white and black rows. Some solutions will see your line take on a symmetrical shape but others have no pattern at all. The difficulty is reasonably well judged with simple puzzles to begin with that let you get used to how to play, before things get tougher throughout the "year" - there are exceptions that occasionally throw off the balancing, though. Stages that use the special tiles can sometimes be very easy, as due to the limitations they impose you may find there is only one way to tackle it.

The game can be very addictive and you may find yourself thinking 'just one more' several puzzles after the thought first entered your head. Even if you do decide to tackle just the one puzzle you may be spending longer than intended on it as you try different things; the solution seeming so obvious when you do finally manage it.

Puzzles can be cleared multiple ways and there is some replay value with the addition of some conditions. Return to a previously cleared puzzle and you will see two flags on screen: one your start point, one your end point. There is also a number displayed indicating the number of steps you should take to do this. Manage one of these conditions and a star will be displayed on the cleared puzzle, manage both and some wings are added too.

Also in the game is a creation mode, with spaces for up to 100 user-created puzzles. Special blocks are not initially available but can be unlocked as you play through the main game. Once you've cleared your puzzle you are given a password allowing you to share your creation with other users – or for you to try out theirs. Handily passwords for from the DS Polarium (oddly released before this GBA entry) can also be used to add user puzzles to your game.

Clearing the puzzles and then completing them whilst meeting the conditions will keep you occupied for some time, but once done there's not much reason to replay the main game. There is however "Time Attack". Here you are given either ten easy puzzles or five hard ones and you simply clear them as fast as you can with time penalties dished out for uncleared rows. There's a leader board displaying the five best times, adding a reason to return to the game as you try to improve your time or beat someone else's.

Conclusion

Some puzzles are very easy, but others require careful consideration and the addition of special tiles adds some variety to the way you play. With hundreds of puzzles to work through as well the time attack mode and a puzzle creation option, there's plenty here to keep you occupied. Polarium Advance is simple to play and also provides a fun mental workout.