411 REFERENCE · Wikibooks
Guide to Game Development/Settings/Gameplay
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
This is going to be a little bit vague as it depends on the type of gameplay that it is.
Difficulty
Easy, Medium, Hard, Impossible (give them a challenge, they'll get more gameplay from it)
References
difficulty gameplay
25%