Handball drill: tennis - special

Two teams of maximum 4 people, 1 ball.
On both sides 2 people in the court, other people behind the back line.

Goal:
score in 1x in the other court (inside the lines).

Rules:
Start with simple underhand service
We play underhand tennis, so in 1x over the net.
Difficult ball may bounce 1x, but then the ball must be returned with : 1 hand, a foot, or the head.

Mistake made => out of the court, to the back line, new player takes over.