After a bit of a chatter on this SoCoder thread, with help from Spinal and RSKGames, I eventually ended up with a spiral-based level selection.



The main menu is now a big bunch of uninteresting looking squares.
The middlemost square is initially unlocked, and as you complete levels, adjacent levels will unlock.

-=-=-

The hardest level of the bunch should theoretically be the top-left level in the grid, but that all depends on how well the level generator is doing at making harder and harder levels!

For now, there's a grid of 81 levels (a 9x9 grid) and that's plenty of levels to keep you busy.



As it stands, I'm finding it frustratingly difficult to test the unlocking mechanic, because the levels are too difficult for me to complete.. Whether that's a good or bad sign, I'm not sure!!