I've fixed the Pezrox problem. Feel free to journey through it and beyond.

In response to some of the questions and comments:
-Yes, I am aware of the bugs, all the work that needs to be done, and the shoddyness of the collision detection.
-Yes, it supports JCS94 levels. And eventually there will be a utility for renaming JCS94 levels.
-The FPS counter is just something I added to see what slowed down and what sped up the game. In the final version, FPS display will be optional. And not on top of the ammo box.
-It now "works" with any version. It works even worse with HH95, though. HH95 is a special case that will require a little more time.
-It would be possible to add Spaz. It would also be illegal, as it would require distribution of copyrighted Spaz sprites.
-Yes, OpenJazz replaces the original executable, and I'm re-programming Jazz from scratch. But why, I (don't) hear you ask?

Two reasons: JJ1 doesn't run on my computer without DOSBox, and it lacks any real support for new levels.

There's a lot more to be gained from this project, for example:
-Multiple OS support. OpenJazz can theoretically be compiled under any operating system supported by SDL, including MacOSX and Linux.
-Higher resolutions
-Multiplayer
-If you know C, anything else you can think of. It will be open source, after all