Definitely give this game a chance!  I've got the instructions below in case you need them after you've already gone through them in the game.  They aren't that bad -- it just looks like a lot at first.  Just read the first ones and jump in.  You can scroll down and read more when you need them. 
This is my new favorite game!  It rocks!!
To answer a FAQ, yes, all the levels really ARE solvable!
Here's a question for you: 
Once you've conquered all the levels, have you done them in the fewest number of possible moves?
If you love Bloxorz, try  Orb 2, Compulse & Spectrum Genesis

If this Flash game doesn't work on your computer, go here for help.
Get a teacher or parent to help!

Game Instructions:

2)  To move the block around the world, use the left, right, up and down arrow keys.  Be careful not to fall off the edges.  The level will be restarted if this happens.

3)  Bridges and switches are located in many levels.  The switches are activated when they are pressed down by the block.  You do not need to stay resting on the switch to keep bridges closed.

4)  There are two types of switches:  "Heavy" x-shaped ones and "soft" octagon ones...  Soft switches (octagons) are activated when any part of your block presses it.  Hard switches (x's) require much more pressure, so your block must be standing on its end to activate them.

5)  When activated, each switch may behave differently.  Some will swap the bridges from open to closed to open each time it is used.  Some will create bridges permanently. 

Green or red colored squares will flash to indicate which bridges are being operated.

6)  Orange tiles are more fragile than the rest of the land.  If your block stands up vertically on an orange tile, the tile will give way and your block will fall through.

7)  Finally, there is a third type of switch shaped like this: ( )    It teleports your block to different locations, splitting it into two smaller blocks at the same time.  These can be controlled individually and will rejoin into a normal block when both are places next to each other.

8)  You can select which small block to use at any time by pressing the spacebar.  Small blocks can still operate soft switches, but they aren't big enough to activate heavy switches.  Also, small blocks cannot go through the exit hole -- only a complete block can finish the stage.

9)  Remember the passcode for each stage.  It is located in the top right corner.  You can skip straight back to each stage later on by going to "Load Stage" in the main menu and entering the 6 digit level code.

Enjoy!!