To launch the game, run packman/packman.exe.
DOS Games made for DOS require an emulator to run on Windows. Use DOSBox or a frontend like D-Fend Reloaded and read this guide to play DOS games on your Windows PC.
Pac PC is a remake of the classic maze arcade Pac-Man, which was one of the most influential games in videogame history. Some info about the original:
Title: Pac-Man
First released in: 1980
Developer: Namco
Publisher: Namco (Midway Games in North America)
Designer: Toru Iwatani, Shigeichi Ishimura
Originally developed for: arcades
These are some of the abandoned games similar to Pack-Man in some way.
Arkanoid
Gremlins
Kingdom of Kroz 2
Aldo Again