This is a fun scenario in which you must defeat three invading British Divisions. Highland Creation Center is a no population limit scenario with a twist; it plays nearly the same as the normal game. You must earn the right to create the units. E.g. You wish to create Paladins. You must have advanced to the Imperial age, researched all the appropriate technologies, built a stable, and accumulated the necessary resources (which will be deducted for each unit created).
It has additional features which allow the game to play in differing ways which dramatically alter the difficulty level. Feature 1 changes the game from moderate difficulty to reasonably hard. Feature 2 makes the game very hard. Features 1 & 2 together make the game almost impossibly hard. Feature 3 is a hidden resource cheat which enables you to beat the game (even as an average player) at the harder levels, albeit with epic battles.
The scenario is complex and has a bit of a learning curve associated with it; but IMHO it is definitely worth the trouble. In all the scenario plays 9 different ways which are described more in the included text file.