Great Promise, but hampered by bugs
I really enjoyed the game, especially the strategy required in using the few points that are given after each level. As you progress, the enemy keeps upgrading and becomes significantly harder, unless you have been keeping up on upgrading your favorite units each round. I also enjoyed the choosing sides aspect of the game, although I haven't played as Medieval Age yet, I enjoy the difference between the two sides, very warcraft feeling, in the mechanics. Medieval has range but hits softer, Dark age wades in and starts taking names.
As for the bugs, as noted by others, at some point the castle will not be destroyed, even though it's health has been reduced to zero. I have reloaded the game 4 times now with varying results, lvl 12 once, 5 once, and 4 twice, all as dark age. Also every now and then, some of my ranged units will decide to run up to the front line and just stand there, getting pummeled, until they drop, or try to retreat. Another quirk with ground ranged units (skeletons) is that they will sometimes completely ignore an air unit, and just stand there getting killed. In addition, the medals apparently do not take into account that you passed them. I have earned the highest kills in a round, but not the lesser medals.
Final note, it would be nice if when the units retreated to the base, they would heal or do something other than just stand there waiting to die. Another nice feature would be a popup message stating that you have received a medal during a match, or during the battle recap. Finally something to tell me the features of a unit on the skills page. I don't know what that precious point is buying, before I start a battle with my new unit, and can see its stats.
Final note to those who worked on this epic project, thank you for raising the bar for flash games. This is not a single setting game, and can potentially provide hours of entertainment. Not many games can offer that.
For those who waded through this, sorry for the word wall.