Hey Andy,
I'm not sure what system Hattrick is shooting on, but I expect it is similar to the one at our local archery shop.
The room is 10-15 feet wide and around 25 yards long. At the far end is a HUGE movie screen. Videos are projected of animals. We can choose what type of hunts to shoot, all white-tails, North american big game, varmits. I like the african safari hunt (I never can hit those baboons though). With ours, up to 3 shooters can shoot at a time.
You have to use special mushroom shaped points (of equal weight to hunting points) so you won't poke a hole in the screen. When an animal walks out and presents a good shot (there are no rings or dots indicating the vital zone or the best angle, just like real animals), you draw and shoot it! Right there on the screen. After each shot (or round) our system shows where the hit was, the speed of the arrow, and gives a score based on location of the hit. The system we shoot on penalizes your score for a bad hit.
I bet there is a system somewhere near you. We used to shoot a couple times each week. I think it was 6 dollars for 15 mins. or 10 dollars for half an hour. Bummer for us is, it has been broke for several months and the shop owners are having a hard time getting it fixed.
It is the most fun you can have indoors with a bow as far as I am concerned.
OkKeith