There are plenty of Pac-man clones programmed in QuickBASIC; some are very close reproductions of the original (such as Pac Classic by Phillip Jay Cohen,) some attempt to modify the level design for better or worse (Hackman 3 by James Robert Osborne,) and many are downright mediocre. Madmix borrows gameplay elements from Ladybug (the 1982 Coleco Vision game) and visuals from the 1987 arcade PAC-MANIA to create a unique spinoff that's still worth giving a shot today.
The very first thing that makes Madmix stand out is its presentation: it is great. The game uses only a handful of colors to produce detailed art reminiscent of old CGA boards, both aesthetically pleasing and readable: walls are sticking out the way they should and moving sprites are smoothly animated. The graphics have a genuine arcade feel to them, which is also the case of the gameplay.
The game features fifteen levels, filled with everything you'd expect to find in a Pac-man clone: pellets, super Pac gums (renamed Angry Pac for the occasion,) a central cage, and ghosts. In fact, the first level is a reproduction of Pac-Man's classic stage, just to drive the point home. But as soon as you reach stage two, new elements are introduced, such as trapdoors (which serves as one-way passages,) Pac lanes (pellets that redirect Pac-Man,) and a brand new creature (a ladybug) that is harmless but will lay down new pellets to replace those removed from the board.
The ghost AI is both challenging and fair: they know how to hunt the player down and when to give up the chase. If only the screen had been slightly larger or some radar was added, it would have been possible to avoid ending up face to face with unexpected enemies. This, and the fact that extra lives are only earned on certain stages (3, 6 and 13) make the game much more difficult than it should.
Finally, the game lacks customizability. While it comes with a level editor and a built-in menu allows loading custom levels, there's no settings (don't forget to view the readme file for key bindings,) no support for joystick, and not even PC Speaker sound.
Even though there's room for improvement (especially in the optimization department,) Madmix is still one of the most interesting take on the Pac-man formula that's ever grazed the QuickBASIC landscape.