Skillshots are lapable and unlimited in scoring possibilities. They are only available from a full plunge.
Skillshots are only available on initial plunge per ball and not available after locks or invisibility cloak escapes.

Standard Skillshot
Score: 1,000,000
Hit the rainbow flashing arrows from the upper left flipper.
Once the ball goes past that flipper the skillshot opportunity is over.

Super Skillshot
Score: 2,000,000
On your initial skillshot if you hit either orbit the ball will return to your upper left flipper again. Hit another skillshot to score a super skillshot. Continue to lap that shot as much as possible to stack up millions.