To a creative mind, carnivals can be highly effective for providing a variety of games (exercises) that allow you to shorten the time between when your brain sees and stimuli and when your brain chooses / executes a response. Shooting galleries are particularly effective games for this. Be it via water guns, pellet guns or arrows with plunger tips. A particular favorite of mine however, is a game which can be so damn fun it should be made illegal: gopher-bopping. If you’ve engaged in such an activity, then I need not explain myself any further. Not only can it develop great short-range reflexes, but do it hard and long enough and it serves as a killer exercise for your forearms.