Nice suggestion! We are still considering what an extra tower could be, imagine that it could be a single non-upgradable bot that helps you a little bit, not a full-fleshed tower! The design options are endless, let's see what we come up with when the full game is ready!
Yes! We are starting to develop a bigger version, and multiple towers are for sure one mechanic that we have in mind! Thanks for the suggestion Jaidyn Edwards!