Level 1: Click on screen (not button), press right arrow key, then once you see the "start" button; press it
Level 2: Click the small button near the bottom of the screen
Level 3: Click the middle square in the column of squares closest to the bottom of the screen
Level 4: Click the rotated pentagon near the bottom right corner
Level 5: Click the second closest to the top triangle (should be near the center of the screen)