panic

I am not sure why we are so eager to apply the idea to games, except that maybe historically games were simpler.

It's because the game is showing you a number and encouraging you to make the number bigger. The natural question at that point is, how big can the number get? The only number Gravity's Rainbow shows you is the page number, which has a clear maximum.

7 years is a long time to work on a single thing. How did you stay motivated to finish? Were there any low points that you had trouble getting through?

How often do you play Threes yourself? What's your high score?

Yeah, puzzles are NP-complete even with just the hexagon dots: you can reduce the problem of finding a Hamiltonian path on a planar graph (which is NP-complete) to a puzzle with dots and gaps.

A lot of games have a "daily challenge" to keep experienced players coming back. One idea might be to pick a random puzzle and random weights for each of the three metrics (each G is worth this much, each cycle is worth that much, each hex of area is worth that much) every day. Then have a daily leaderboard for who found the best solution according to that combined metric.