There are so many possibilities for tower defense games. I would not take from existing tower defense games (such as Tower Defense Simulator took from Tower Battles). BelowNatural (Creator of Tower Defense Simulator) got a ton of hate from people for taking the majority of TB’s ideas and renaming them into his game. I would think of unique towers and enemies and go from there.
This will have different rounds and enemy’s this will NOT be a copy from the existing Simulator game. This is mostly for me and my friends to play anyway.
That is why I asked to make sure to have different gameplay, you probably don’t want to make a game, and then have many people leave, due to it already existing.
Looks good, I don’t think the turning is an issue, the NPC is just spawning. But, maybe put some effort into the zombie models? Because they are just colored, maybe add 3D clothing and some details on the body. Other than that it looks good.