This was a rebuild of a 3-day project I did back in 2015 as part of an interviewing process (I got paid a flat $300 at the time).
So a lot of the concepts and ideas carried forward, along with a non-zero amount of code, but as my architecture was different, it did need to be updated, even if some of the math and logic didn't change (this was strictly limited to the modular components and reusable utilities). Definitely have cooler enemy models this time around, though the tower models got less so. Little less variety this time around too, ran out of time.
Models are all free assets off the asset store or hand-built from Unity primitives.