I like this one, I can see where the inspiration comes from, and it's a suitably small scope for such a short dev time.
Maybe I was just bad at the game, but it felt like the enemy numbers ramped up a lot and I ended up stuck using the priest to defend the camp (although at that point there didn't seem to be any goal anymore either, could maybe use some kind of ending, now it feels unfinished).
It wasn't entirely clear in every aspect, like the level up powers weren't obvious as for what they do, and it wasn't clear if the archer only hits the first enemy in sight. Also I didn't understand why sometimes I ended up with a "ghost" ninja stuck in places, was it a bug or the chosen upgrade's feature? But that's a challenge with the chosen genre which usually uses lots of text to explain mechanics.
Overall it was enjoyable albeit a little unpolished.