Linelight

Secret stars are green stars that do not appear along the regular path whilst playing the game. They are hidden areas, that unless you know where they are then you are very unlikely to stumble across them. There are 6 green stars to collect in world four. Collect them all to earn this trophy.

The star grid puzzle in world 4 can appear to be extremely tricky, but it is just about waiting for the right moment to move. If you watch the red light on the middle column you can see each time it reaches the very bottom it very slightly moves position in compared to the right lights circling the perimeter. You need to be quick, but this is the key to this puzzle.