The NetHack source code has grown considerably since Hack 1.0:

Version	Lines of code
Hack 1.0	14,652
NetHack 1.3d	28,916
NetHack 1.4f	29,525
NetHack 2.2a	31,334
NetHack 2.3e	32,891
NetHack 3.0.0	60,939
NetHack 3.1.0	96,688
NetHack 3.2.0	115,858
NetHack 3.3.0	132,643
NetHack 3.4.0	145,530

Method: wc -l src/*.c include/*.h

For comparison, the Linux kernel source is 1,322,955 lines.