Greencastle is a very small town, but there are some fun places to eat and the campus of DePauw University is nice.
DePauw has put together a great guide of things in Greencastle https://www.depauw.edu/about/campus/visiting/
The Fluttering Duck
2 West Seminary Street, Greencastle, IN 46135, (765) 658-1006
DePauw Nature Park
1400 West County Road 125 South, Greencastle, IN 46135, (765) 658-1076
DePauw University
313 South Locust Street, Greencastle, IN 46135, (765) 658-4800
TapHouse Burgers
24 South Indiana Street, Greencastle, IN 46135, (765) 301-9326
Almost Home Restaurant & Bar
17 West Franklin Street, Greencastle, IN 46135, (765) 653-5788