O-kay, forgot something

In preparing for show-and-tell at Philly Game Mechanics, I found that I hadn't dealt with the "Player loses" situation. I've added a "Game Over" and solved a nagging concern about file size. The MacOS version still requires about 230 MB of disk space when decompressed, due to the need to support both Intel-driven Macs and the new "Apple Silicon" (M1; a desktop-grade variant on the ARM architecture) ones.