I am unsure whether this is caused by my computer or the game itself, but I experience quite low FPS; the lag makes the controls feel uneasy. In case this is not due to my material, it could maybe be a good idea to use less heavy assets and/or see how to optimize the rendering?
Alas, the QWERTY-AZERTY curse striked again!! (I am saying that, because I have recently been stumbling upon a series of games that behave like this.) I have an AZERTY keyboard, and the WASD keys were coded symbolically in the game, instead of physically. To give you an idea, my A is your Q for left, which is still manageable, but my W is your Z for up, which is not handy.
I like the castle and the music; on the other hand, the action seemed a bit confusing to me. As a suggestion, perhaps you could design an architecture that sets the two camps apart more clearly (I don’t know if this is really a good idea), and differentiate the enemies from our allies even more?
I like the final shot that lets you peek at the roof during your final moments lying down, especially focusing on a candelabrum; I was pleasantly surprised by that one! :)
As for the constraint: well, it is true that this type of game matches the requirement, but I feel this is too conventional an answer. This may be me, but I see the constraint as asking for some kind of twist.
I tend to think that having complex 3D is hard to manage, especially in a short game jam timeframe, and your account of how things went on the page for the game seems to confirm this view. If you get to hone skills out of it, that’s great. Congratulations on having your own first project! :)