Tefris app for iPhone and iPad

The object of the game is to create chains of same-colored blocks and then collide different colored chains together.

Pick a block from the three displayed at the top and drop or throw it down into the container. A new block will then be offered at the top and one of the remaining two will be replaced with a new block.

If two same-colored blocks are touching each other they will be marked by a border - they have begun creating a chain of that color. Once a chain reaches four members each of its blocks will be marked with an X - meaning that the chain can be collided with a different colored chain.

When two chains of different color collide the blocks are marked to be collected. This takes a little while (6 seconds at full FPS) and blocks that are marked to be collected can still be used to build longer chains. Once all blocks have been collected points are gained for them and are added to the score.

The number of points rewarded increases exponentially with the number of blocks collected and with the number of colors involved. There are five colors available in the game, plus a white "joker" color that counts as all colors that touch it (but cannot create a white chain by itself).

There is a red line present that constantly moves towards the bottom of the game area. This red line removes all blocks that touches it and once it is at the bottom the game is over. It will gain speed for each block that it removes, and also deliver a penalty movement burst. By colliding chains the red line is reset to its original position, however its speed is never fully reset meaning that it will eventually reach the bottom of the screen even for the fastest player.

Every time at least 5000 points are gained a shockwave is earned. These appear as black dots in the top left corner, on the easy and medium difficulty you begin with some of these.

Shockwaves can be used to freeze the movement of the red line and to nudge blocks. Simply touch down on the game area to deploy a shockwave (freezing the red line). When releasing the shockwave will have its effect and the red line will unfreeze. Note that the red line will still remove blocks when frozen, and any penalty speed boost from removed blocks will have its effect once the shockwave is released.

There are two ultimate goals of the game. The first is simply to beat your own or your friends highscore. Topping the list will require good decisions, reflexes and a steady aim. The highscore list is local.

The second goal of the game is to pass the eight different challenges for each difficulty level. These are displayed in the menu (accessed by pressing in the lower or top right corner of the game area). A percentage number is displayed for each challange so that you will always know how far you were from passing a challange each game.

Features eight different maps, three different difficulties and a highscore list for each map (one for each difficulty). The eight challanges are adjusted depending on set difficulty, and remembered separately.

The game works for all ages. It provides a fun few minutes of brain exercise for the adult and provides a good learning experience for the child.