As a tower defense enjoyer, I wish it had more! It felt like I was playing bloons again lol
When it comes to unit variety, I felt some towers were kind of underwhelming, on the other hand, the wizard tower's effects were pretty cool.
I think ultimately the game is one that could really use a lot of polish. Hopefully by post jam you have all the time to add audio, fix some typos here and there, and maybe add some more interesting things that the tower can do upon upgrading, rather than just a stat boost of some sort. That would make the game very fun.