I think the 10 years is the key here. 15+ years ago the DevC++ was a gem, lightweight, fast usable IDE. But 10 years ago there was the free VSExpress out (not even the first, 2005 and 2008) which was far superior to DevC++ imho. (edit: on Windows)
The size limited demos are use techniques like in the OP, scrapping the runtime, no std, filling the unused exe header sections with own data, quantizing floating point values, etc. And/or exe packers like Crinkler and kkrunchy.
COM's are no longer used.
I can recomment HROT, it is still in development but you can try the demo on Steam. It is awesome.
Fun fact: it looks like Quake engine but not, it is written in Pascal.