Here is the full list of all 16 Blobby Tennis achievements.
Play the ball back and forth 5 or more times.
Score 1 point against Blobby.
Score 5 or more points against Blobby in one session.
Score 10 or more points against Blobby in one session.
Score 25 or more points against Blobby in one session.
Play the ball back and forth 10 or more times.
Play the ball back and forth 15 or more times.
Play the ball back and forth 20 or more times.
Play the ball back and forth 25 or more times.
Play the ball back and forth 50 or more times.
Bounce the ball 10 or more times on the racket.
Bounce the ball 25 or more times on the racket.
Bounce the ball 50 or more times on the racket.
Bounce the ball 100 or more times on the racket.
Bounce the ball 500 or more times on the racket.
Hit the radio with the ball.