Cubixx HD

Can be done on level 1. Just start cutting away a tiny piece of the cube (2x2 or 3x3 as to not risk touching your own line) and you've got three lines right there. Repeat on and on and on and on until the trophy unlocks. Cutting away small parts is the way to go since doing bigger ones would put you at the risk of completing the level BEFORE getting the trophy. Should you THINK you did it and it didn't unlock and you complete the level in frustation... remember that the end of level recap screen tells you EXACTLY how many lines you used and this will help you see how you must be a bit more patient the second time around.