Blek

• The speed that the line moves is determined by the speed that you draw it. Try drawing very slowly and watching for problems in difficult levels.
• To make your line move straight, make sure its ends are even. A diagonal angle will cause the line to move off horizontal. This is critical if you are creating an arch. If one end of the arch higher than the other, the line will be unbalanced. The ends of an arch must be the same length in order for it to move straight across the screen.
• Make sure the end of your line does not contain extra movements, which may cause it to move off course.

When a line overshoots the dots to the left or right, it may bounce back and collect the dots while returning. However there is no such "wall" on the top or bottom. Your line will continue as long as possible (until touching a black dot or moves off the top or bottom).
asai

To create a portal, quickly draw a perfect circle. If done correctly, a black vortex portal will appear instead of a line. You can draw multiple portals as well as a line. When a line enters a portal, it will emerge from the next portal. To remove a portal, just tap it.

• Lines will repeat your movements immediately after release. To release a line, lift your finger or draw it into a colored dot. The line will collect the dot and immediately follow your drawn pattern. Note: You cannot draw through a colored dot because the line will release.
• Lines will automatically release after approximately ten seconds.