The demo programs at this site are amazing feats of programming. I never even knew it was possible to create vividly rendered 3-D landscapes with cool lighting effects along with quality synthesized music in an executable file no larger than 65KB. There’s also a first-person shooter game here called kkrieger that’s only 96KB. It too is amazing. Be warned though. Although these programs are clean and very safe to run, some of them will generate false alerts from your anti-virus program so you probably won’t be able to see some of these feats of programming in action.