When throwing, two players play against each other. The one who 'holes' the three snowballs faster is the winner. You could also call it a kind of bowling, mini golf or curling.
That sounds very simple at first. When the system is switched on...
the targets are blocked by sticky pistons. The pistons are connected to different fast clocks per track. So there is a need for skill in timing.
If a player goes too close to the lane, i.e. oversteps, the piston locks as long as you stand on the pressure plates.
If the player hits, the lane is blocked and the redstone torch lights up.
The first player to complete all three lanes is indicated as the winner by a redstone lamp.
A bit of Redston and fairly basic Clocks in the basement.
until the next idea.