How big is your engine in lines of code? Just curious.
My entire workspace is 68,400 lines, not lines of code but raw line count of all *.java files - so it's a bit susceptible to the formatting style. This represents ~5 years of active development, a couple of significant refactors, and 9 games worth of left-over bits and pieces. I haven't worked on this engine for a few years now, except for the 7DRL game jams because it's more complete and capable than my current project.