Singleplayer (For Devs)
1. Fun > Realism. Always. And. Forever.
2. Do not use backtracking as padding.
3. If your game is too short, cut the price a bit or make more real content.
4. Enemy health should be within reason.
5. Do not make me find hundreds of hidden stars to get the best ending. Make me play through the main story perfectly.
6. If you are to infinitely spawn enemies, tell us clearly. (Or don't do it at all.)
7. DLC should make a game better than good, not bring it up to standard. (ie. Patches are not DLC)
8. If you're planning to sell DLC for $20, don't. $5 is plenty.
9. If you set up a sequel, make one. Even if your first game bombs.
10. Do not clone other games. There are enough original ideas left.
Multiplayer (For Players)
1. Don't be a dick.
2. Go easy on new players, allow for their lack of skills and encourage them to keep playing.
3. Do not use any weapons/tactics that are hopelessly broken in a friendly game.
4. If you must swear when you die, turn your mic off to do it.
5. If you're miles ahead, screw around and use some new tactics to give enemies a chance.
6. Share resources/powerups/ammo with your teammates.
7. Never try to be Leeroy unless your teammates are treating everything like SERIOUS BUSINESS.
8. Accept that you might just suck. Not every other player is cheating.
9. Don't teabag or trash talk your opponents, unless they're in the same room as you.
10. No hacking or glitching.