Engagement

What keeps a player playing once they start β€” 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 β‰  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 β€” creative direction, theme, central fantasy.

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

One-note tones compete with everything. Animal Well is cute *but* mysterious β€” 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 β€” your inspiration should too.