Cobalt

Here is one Curve Data puzzle.

Chaos

Here is one Curve Data puzzle.

Puzzle

Here is one Curve Data puzzle.

Frolic

Here is one Curve Data puzzle.

Beetle

Here is one Curve Data puzzle.

Serpent

Here is one Curve Data puzzle.

Masyu Inflatable

Here is one innocent-looking 5 by 5 Masyu puzzle:

Inflate it to twice its original size, though, and it turns into a full-blown 10 by 10 Semi-Liar Masyu:

Cipher Shikaku Twins

Here is a pair of Cipher Shikaku puzzles.

Masyu Twins

Here is a pair of Masyu puzzles.

Star Battle Pentominous

Here is one Star Battle Pentominous puzzle.