The cuboid is easy to make, because you don't have to extend any pieces.
Check out step 5 to see, how to solve it. Basically it solves like the 3x3x3, so if you know how to solve that one, you should have no problems. A big advantage compared e.g. to the Fisher Cube is, that there is no parity.
Also you can easily shove it into your pocket because it is a lot thinner than the original cube.
Step 1: What you need
material:
 A black Rubik's Cube (Best is a DIY Cube, because you can easily assemble and disassemble it. Also it comes with a set of stickers, which you can later use). You can of course use an assembled cube, but you will have to get rid of the stickers, before you start.
 selfhardening synthetic clay (I used “Apoxie® Sculpt”)
 Tiles or stickers (e.g. from cubesmith.com). Just get the regular 3x3x3 sized ones. Tiles are better, because they can compensate small irregularities.
 a Dremel (Felt Polishing Wheel, SpeedClic Plastic Cutting Wheel) if you don't have a Dremel, just use a regular saw
 sandpaper (400, 800, 1000)
 a black permanent marker

a box cutter
That isn't a cuboid, it's a shape mod of a 3x3. It may look like a cuboid with only a 2x3 grid of stickers, but you have to include the corner to the left of the blue, orange, green, or orange face. if it moves like a 3x3 but doesn't shapeshift (like a REAL cuboid, e.g. 2x2x4), or has a sum of the grid X + grid Y + grid Z not evenly divisible by at least one of the grids (if the sum of three grids/grid x, the sum of three grids/grid y, and the sum of three grids/grid z equal each other, you have a cubic puzzle, and you can now use that for calculating the volume using two numbers and you can calculate the third. You're welcome.
I know that cube is in the game Adrenaline!!!
Do you mean the companion cube? It is part of the game portal.
Love your instructables by the way
mabe you find it somewhere else. I got that one for Christmas!! :D