Shrek - W to jump, A to go left, D to go right, S to attack. Kermit - Up Arrow to jump, Left Arrow to go left, Right Arrow to go right, Down Arrow to attack.
Click the flag 3 times. Kermit attacks slower but moves faster, jumps higher, and has more Hp than Shrek. Shrek Attacks way faster but has less Hp than Kermit.