In general, game sessions should be as short as 10-15 minutes. A complete and successful playthrough should be somewhere in the range of 10-60 minutes.

Mini-games

A short (1 to 5 minutes) bit of gameplay that either directly benefits the playthrough by completing some immediate goals or provides the player with some insight on their current playthrough.

Look and feel

In general all mini-games should feel like they are “a part of the same game”. Win conditions should be meaningful to each individual playthrough. Failing a mini-game may have different effects on the playthrough, ranging from “bringing closer the hard lose condition” to “temporarily disabling some player choices”. Examples of good implementation:

• FTL
  • Crew management
  • Time and space awareness
  • Map navigation (choosing what happens next)
• Slay the Spire
  • Card game
  • Deck building game
  • Map navigation (choosing what happens next)
• Risk of Rain
  • Action platformer
  • Gameplay altering mechanics on each character
  • Unique boss mechanics
  • Unique level mechanics
• The Binding of Isaac
  • Twin-stick shooter
  • Unique enemy and boss mechanics
  • Gameplay altering power-ups (and their combos)
• Factorio
  • Iterative resource management
  • Iterative space management
  • Iterative time management
  • Tower defense
  • Shoot’em up
• Stardew Valley
  • Time management
  • Resource management
  • Distinct activities (farming, foraging, mining, fishing, animal husbandry, etc)
  • Quests
• Katana Zero
  • Action platformer
  • Unique boss mechanics
  • Gameplay altering characters (only 2, but still)

Examples of poor implementation

• Stardew Valley
  • Romance
  • Casino
  • Arcade machines
• World of Warcraft (retail)
  • Pet battles
  • Archeology
  • Garrisons
  • Artifact weapons
• Katana Zero
  • Bike mini-game
• Space Rangers 2
  • Whole RTS part
  • Text adventures