It seems that you're using an outdated browser. Some things may not work as they should (or don't work at all).
We suggest you upgrade newer and better browser like: Chrome, Firefox, Internet Explorer or Opera

stijn.443: The Jazz Jackrabbit 2 Collection contains a JJ2+-enabled version of The Secret Files as an optional download, which is super cool, but unfortunately this alternative installer doesn't install the original Jazz Jackrabbit 2 single player episodes. Would it be possible to include those in the package as well?

Could you send us a Support ticket with all the things that are missing?