Definitely has potential!
Things I really liked:
The idea of balancing everything to defend is really cool. Solid idea, and when it clicked I started seeing the potential. The idea of a tower defense where you are forced to balance your building decisions in this way is novel - since most tower defense games typically force you to change strategies due to enemy types or map layout (or just optimizing the best common strategy). Instead, you added an implied layer of politics. I dig it.
Things that could be improved :
This is mostly due to being a jam game, but the tutorial screen throws so much information it's hard to really get a grasp of what everything does in game. I would use some simple iconography above each purchase during the game to give the player an easier way to remember all the different things you can buy. Tool tips would be even better (but a bit time consuming for a game jam).
The very first time I played, I bought a tower and some guys....and soft locked because I wasn't generating money or mana. I would either place some of those buildings at the start automatically, or lock out all purchases except those in the beginning to lead the player to starting an economy - then unlock the other purchases. This would also create a progression system.
Spawn the attackers later as waves. Given an indicator that the wave is starting. The frantic pace could be good, but the attackers spawn so immediately and so quickly that it's very easy to get overwhelmed and not even attempt to focus on the strategy of balancing the clans.
I know that's a lot of "improvements", but hear me out:
This idea is neat, and I think you should polish it up, and just alter the game loop a bit to something a bit slower paced and more structured. Good work!