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I read and watched a lot about game feeling beyond many I liked these best
- Jan Willem Nijman - Vlambeer - "The art of screenshake"
- The art of screenshake
- Juice it or lose it - a talk by Martin Jonasson & Petri Purho

Game feeling is how you experience your interaction with in a game. Does jumping feel good? Does the gun have a powerful feeling when using it? Is it satisfying when you destroy or kill something? Does it have a snappy control? Was it exiting to solve that puzzle?

Jan Willem Nijman has 30 tricks to juice up a shooting game:
1. Basic Animations & Sounds: Makes the walking, jumping, pickup things and shooting more fun.
2. Lower Enemy HP: It's more fun.
3. Higher Rate of Fire: It's a video game about shooting so put more bullets in there.
4. More Enemies: Because of trick 2. you need more enemies to shoot.
5. Bigger Bullets: Don't use realistic sized bullets as it looks so silly, make them big.
6. Muzzle Flash: Just make the first bullet frame a circle.
7. Faster Bullets: Slow bullets are lame, make it faster.
8. Less Accuracy: If your gun is not too accuracy it looks more realistic and is more fun.
9. Impact Effects: Let the player know he hit something, don't just remove the bullets.
10. Hit Animation: Let the player know that he damaged the enemies.
11. Enemy Knockback: But knock back force if you hit enemies.
12. Permanence: Don't remove dead bodies, it helps you remember if you come back in a room with a hug pile of dead bodies in it.
13. Camera Lerp: Smoother cameras make the character feel more in-motion.
14. Camera Position: Your your camera to focus on important things in your video game.
15. Screen Shake: This is an important rule add screen shake on explosions it looks so much more powerful than without.
16. Player recoil: Shooting feels much more powerful with recoil on the player and you can use it to avoid that player do not shoot all the time as it has a drawback.
17. Sleep: If you set a deadly hit sleep for 100 or 200 ms, it puts more meaning in that action, brawl games do that a lot.
18. Gun Delay: Make the character and its props look like they have weight/momentum when moving.
19. Gun Kick: Add recoil to things that would have it.
20. Strafing: If you shoot and change direction the shooting will be still in the same direction until you stop shooting to turn around the gun.
21. More Permanence: Put ejecting shells in your game and make them permanent, it also helps to remember that you where in that room and that you did shoot a lot.
22. More Bass: Add bass to your shooting and explosions they get much more meaning and power.
23. Super Machinegun: Try ridiculous variations on how shooting performs, maybe three bullets a time, go cracy.
24. Random Explosions: That is a funny one but it puts more action in your game if you put some random explosions to your game when you shoot enemies, don't over due it.
25. More Enemies: You tuned up your game play so that you got the feeling you have not enought to shoot at.
26. Even Higher Rate of Fire: Because it is more fun to shoot
27. Even Higher Rate of Camera Kick: Make your camera cick in the direction of the action/shooting.
28. Bigger Explosions: Seriously, who doesn’t like explosions.
29. Even More Permanence: Put some dust after your gigantic explosions and let it fade slowely.
30. Meaning: Let your player win or loos.

I found some more tricks in 3D world like
31. Flash light: Add a short bright light flash on explosions it feels more realistic and more boom, it looks good even without sound.
32. Add more light: Add a following light on rockets, it makes it more vivid.
33. Hit points: It is satisfying to see how much damage you applied with your shooting, visualize it instantly on the location of the hit.