Move two ninjas through the pattern and activate all blocks before you reach the key blocks. Both ninjas should stand on blocks, so make sure you plan each your following move.
Have you ever played for a ninja? How about playing for two ninjas simultaneously? This sounds weird, but that's easy and you can See it for yourself. Play the game and lead two ninjas through the levels, full of traps and various obstacles. Can you get all stars and keep both ninjas alive till the tile will be activated.