Since I anyway wanted to tell you what I though about this game, I decided to write this review. First of all I wanted to try it out since the screenshots looked promising, and especially since it was just pure TI-Basic.
You can call it a bit slow, but for a TI-Basic program I was pleasantly surprised by its speed. In my opinion the game responded pretty fast to my key presses. There are definably missing features in the game, but knowing ahead it was just a demo, I found room enough to explore and enjoy myself. Also the monochrome sprites and special effects look just amazing. If there are any people hesitating to download this game just because of the lack of grayscale: Man, you really won't miss it!
I know that using giant matrices like a map can really slow down a program, so I'm still wondering how exactly you did it, since it's always snappy.
The only cons about this program I can give is that a Readme was missing, so I had to figure the controls myself out, but then again, they were pretty easy to discover. Also sometimes I did get a memory error, so the people trying this program should perhaps delete everything from their calculator first since it is also a bit heavy on files. But who am I to talk?
So TI-Basic lovers, go play this game! There's a very big chance this will stay a demo forever, but it really is something I think you should try. Congratulations to the author for making it!