I like tower defense games, and though this was short that is understandable. I'll start with the bad stuff, the music was too jarring after the first loops, the only reason I didn't end up muting it was because I finished it before i bothered to, and the tower selection, though fine at first, leaves a lot to be desired, especially in balance, with the enchanted lantern being the only one really needed, the ballista being close to useless, and the holy water gun being inconsistent with its firing to the point that I saw it aim toward a spirit without firing and letting it pass all the way through.
However, It has promise. I liked the concept itself, the idea of being a spirit medium, and better polished it could end up being a good all around game.
Some tips I would give is making towers shoot where the enemy will be instead of where it is, this is especially necessary with the ballista as it misses constantly. Maybe give less damage to the enchanted lantern, or a type of enemy that is immune to it. With such a small selection of towers, it's important to give every one a legitimate use, and make using only one very difficult if not impossible.