Rearrange and rebalance the maps

[olofson]

The maps should be reordered, rebalanced, and redesigned as needed to gradually introduce new techniques and strategies. The player should be given fair chances to learn how to use these features before really being forced to use them effectively.

This becomes more important with new features, such as #342 and #168, which enable new ways of solving some maps, and occasionally inspire play styles that can backfire brutally.

All that said, the replay/rewind logic helps a bit here, as there is always the option of rewinding and trying a different strategy. Let's just not abuse that too much.