MiniTee is a miniature golf course consisting of 18 holes with an increasing difficulty. You can either play it all by yourself or compete against friends. Take turns and keep track of the score for each player to be able to select a winner by the end of the game. It uses simple redstone mechanisms to ensure nobody cheats (like tripwires) and holes are actually hopper which collect the balls (or rather snowballs).
Take a golf ball from the chest at the first hole. Then stand behind the tripwire and drop the golf ball on the course. The ball will slide on the course until it hits a stop.
Walk on to the golf green, pick up the ball and throw (or rather drop it) again. This time it dropped neatly into the hole. To really be sure, tap on the hopper (or hole) to collect the ball.
Make sure to keep count of your total strokes for each golf course. You can learn more about the scoring system by returning to the lobby and read the description there.
In total there are 18 holes which needs to be finished to complete the minigame. By each level things definitely get more challenging.