Okay, so admittedly, I'm not the greatest at these tower defence/hero management/Might and Magic-style games. I find that they all tend to expect the player to know what to do right out the gate, and if you haven't min/maxed your movement by turn 3, you might as well restart because you'll never regain the distance the AI has on you because even on easy mode they're often min/maxing every possible action, they're just often dumbed with resource allocation and offensive strategies.
Thankfully, this game is not like that, but it's certainly not easy either. Now again, I do suck at this style of game, but by day 10, the enemy was already coming at me with spectres, and I hadn't even built a granary for the second tier of units, let alone the third (spectres). I found that the rate they were pumping out barbarians was faster than I could put them down because I was trying to divide my forces between fighting and resource gathering, and I could not find the right balance, clearly.
HOWEVER, therein lies the theme of the game: your hero is... kind of expendable???? Like in this style of game, losing your hero is catastrophic, usually. But here, it isn't nearly as heavy a loss as it normally is, as you get a bunch of stuff from it, so that definitely helped out. Once I knew I didn't need my hero babysitting the fort and could actually send him out to go crack some skulls and gather coin, it became a lot more manageable as I actually had stuff to build with. I still didn't WIN in the end, but I came close.
Overall, I'd say your visuals are good, the art is good, the core gameplay is exactly what you took inspiration from and the game functions very well with clear instructions on what each unit does, with each of them being varied enough to feel useful and necessary. Add in a bit more music and maybe have it a bit less 2005 era grim dreary middle of iceland in autumn, heavily overcast about to rain vibes with the landscape, and you're set IMO (obviously more content/levels too, but like, for a 5-day game jam this is damn impressive to put out!)