XEODesign
Official site of Nicole Lazzaro’s company where you can find a lot of presentations and videos about 4 Keys to Fun.
Immersyve
You can find here a lot of researches (or links on researches) about player engagement and motivation.
The 5 Domains of Play: Applying Psychology’s Big 5 Motivation Domains to Games
The first part of GDC lecture (GDC 2012) from Jason VandenBerghe about using of O.C.E.A.N. personality model in game design.
Applying the 5 Domains of Play: Acting Like Players
The second part of GDC lecture (GDC 2013) from Jason VandenBerghe about using of O.C.E.A.N. personality model in game design.
Attention, Not Immersion: Making Your Games Better with Psychology and Playtesting, the Uncharted Way
GDC game design lecture from Richard Lemarchand about Attention, Engagement, and Immersion in games.
The 4 Keys to Fun and the Psychology of Engagement
Lecture from Nicole Lazzaro about 4 key emotions that drive the player engagement.
The Science of Fun: 3 Ways Games Make You Happier, Save the World, and Drive Retention
Casual Connect lecture from Nicole Lazzaro about 4 Keys to Fun with a focus on the neurophysiology of key emotions.
The Four Most Important Emotions for Free to Play Casual Games
Casual Connect lecture from Nicole Lazzaro about 4 Keys to Fun with a focus on monetization of F2P games.
The 4 Most Important Emotions for Social Games
GDC lecture from Nicole Lazzaro about 4 Keys to Fun with a focus on social game mechanics and social games.
Precision of Emotion: A New Kind of “Fun” Approach
GDC lecture from Erin Hoffman with an interesting model of “Fun”.
Intrinsic and Extrinsic Player Motivation: Implications for Design and Player Retention
GDC lecture from Scott Rigby (Immersyve) about Autonomy/Relatedness/Competence – the main components of the player long-term motivation.
The Applied Value of Player Psychology: Putting Motivational Principles to Work
GDC lecture from Scott Rigby and Troy Skinner about player motivation with a focus on Competence, one of the most important components of the player long-term engagement.