Engagement

What keeps a player playing once they start — moment-to-moment activities and the feel of them.

A great toy beats a great structure. If swinging the sword in an empty room is dull, no amount of level design fixes it.

Harder ≠ more interesting. The decision matters only if both options cost the player something real.

Pretty Unity/Unreal scenes are not engagement. Atmosphere wears off in minutes if the activity loop is missing.

Appeal

What makes a stranger want to look at your game in the first place — creative direction, theme, central fantasy.

Pacific Drive is "look after a cool car in a weird sci-fi zone" — that fantasy explains the mechanics, not the other way round.

One-note tones compete with everything. Animal Well is cute *but* mysterious — that combination has fewer neighbours.

Mini Metro pulled from subway map design. Pacific Drive from Knight Rider and Back to the Future. Your players have rich lives outside games — your inspiration should too.