I'm a ti-89 user, and I like mine real well...
Since you've archived them, I assume you know how to get to the screen with all the files on the calculator. Since this is an assembly game, the files with extension .89z are the actual asm files, and the ones you need to concern yourself with. Once they'll on the calc, you'll see them with the 'extension' of asm; these are essentially the executable files. As the other asm files seem to be level editors and such, you simply need to highlight the arena.asm file, press enter, and then add a parenthesis once back on the home screen to run it.
Stallion- yes, they have lots of games for all the TI calcs on ticalc.org. You will need to buy a link cable first, though to link to the computer.