Introduction: Reacting Game

This is a game that trains your reacting speed in two ways. It's recommended to people that want to train their reacting speed or have fun with their friends. First, two players would have to compete against each other to see who presses the button first. Whoever presses the button slower would get shoot by sticky hands. Secondly, players can train their reacting speed by dodging the sticky hand. Below are the process of making the game, hope you enjoy!



  • Scissor
  • Utility knife
  • PP plastic board (at least 100cm x 60cm)
  • Wooden ice cream sticks (1cm x 10cm)
  • Paper or plastic board (30cm x 38cm)
  • Glue gun
  • Tape
  • Rubber ban
  • 4 paper clips
  • 2 or more sticky hand toy
  • Sewing needle
  • Thread
  • Thick cloth (backpack rope)
  • Long toothpicks

Step 1: Stick Paper Clips on the Servo Motor

  1. Bend the paper clips as the picture shown above
  2. Stick the paper clips of both sides
  3. Stick tape around the paper clips

Step 2: Make Two Slingshots

  1. Use scissors or utility knife to create two dents on each wooden ice cream stick
  2. Glue two sticks together with a glue gun
  3. Cut two rubber bans in half
  4. Tie rubber bands on both dents
  5. Tie the two rubber band together
  6. Cut the cloth (backpack rope) into two pieces of 6cm
  7. Sew the two pieces of cloth together (shown in the video)
  8. Wrap the tied rubber band inside the cloth and sew it
  9. Sew the left and right hand side of the cloth to make sure the rubber band is in the middle (shown in the video)
  10. Sew a circle in the middle to hook on the servo motor (shown in the video)

Step 3: Cut PP Plastic Board

  • 30cm x 38cm x1
  • 30cm x 6cm x2
  • 38cm x 6cm x2
  • 30cm x 25cm x1
  • 30cm x 15cm x2
  • 25cm x15cm x2

Step 4: Fix the Sling Shot and Servo Motor on the Board

  1. Take five wooden ice cream sticks and cut off their round heads (take three of them and cut into half)
  2. On the PP plastic board, leave 6cm in the front and back (see image 7), and stick the slingshot on the board with a glue gun
  3. Add the cut ice cream stick to support the slingshot (see image 3)
  4. To measure the distance between the slingshot and servo, hook the circle on the servo motor and pull (see image 4)
  5. Cut a rectangle that fits the bumped part of the servo motor
  6. Glue the servo motor on the board with a glue gun

Step 5: Poke Holes

The hole at the bottom:

  1. Cut a hole about 1cm x 1cm at the bottom of the board for wires to go through

Holes at two sides:

  1. Take the 30cm x 15cm board and measure the place sticky hand shoots at, about 8cm x 8cm (see video 1)
  2. Cut the hole with a utility knife

Holes for lights:

  1. Draw four circles on the side (see image 2)
  2. Take a small screwdriver and heat it on the stove and poke holes

Step 6: Wiring

Wire according to the graph above.

  • Add extension wire for the lights, light sensors, buzzer, and servo motor
  • Stick the wires at the bottom of the board so it doesn't affect the game's function

Step 7: Stick the Box & Cut Holes

  1. Stick the final pieces of the box together
  2. Cut a hole on the side for the buzzer to fit and stick with tape
  3. Cut holes for the buttons at the middle and stuck the buttons in
  4. Cut two 3cm x 5cm rectangle, one on each side of the button
  5. Cut four 3cm x 5cm white PP plastic boards and stuck them into their holes
  6. Stick the light sensors below white plastic boards as image 6
  7. Cut a 30cm x 38cm board and stick it at the bottom
  8. Make the roof by poking one or two toothpicks (so it can be opened easily)

Step 8: Coding

Step 9: How to Play


This game is for two players, two players will sit at opposite sides facing each other. When both hands of both players put their hands on the white rectangle, the game starts automatically. The lights and buzzer will light and buzz at a random pace. As the green light lights up, two players have to hit the button in front of them as soon as possible (you have to hold the button for at least 0.5 seconds for it to work). However, the servo motor will turn and shoot the sticky hand to the person that hit the button slower. As the green light fades after five seconds, you can restart the game. But in each round, you will have to hook the slingshot on the servo motor again and place the sticky hand on it. (tip: the sticky hand can shoot further if it's nicely placed like a ball)

The video above demonstrates what it looks like during a game.