Definitely interesting for the nearby towers to modify existing towers. Like one of the other commenters I did pretty much give up when the very last enemy from level 3 was the only one to make it to the exit XD But then I went directly to level 10 to sightsee.
I think I would have liked to see a benefit to the towers that needed the other towers nearby - perhaps instead of needing them just to fire at about the same rate / with about the same projectile, they'd be enhanced or something in some way - just to incentivize that. But definitely kudos to you for making a tower defense for the jam ^_^ Thanks for the experience!