Wow I didn,t know phones could take pics that big. O.o

Also perfect grayscale isn't necessary. Just as long as it doesn't look terrible when scrolling to the point where we barely distinguish anything.

Many phones have 3MP cameras now

The graphics look great!

Sorry happybobjr I don't like converted sprites in general.
Also, my phone camera is 5 megapixels.

Here's a screenie and a demo of what I've got so far.  I'm aware of quite a few of the issues with it, and I'm actively working to resolve them.  The digging mechanic will be done quite a bit differently, and right now I'm not showing the animation for digging or propeller movement (both of which are implemented and commented out).  I'm also going to make the HUD much prettier, it's only a placeholder to ensure test out my ideas for reserving a portion of the screen for non-map stuff (which was difficult because of my tilemapping technique).  I can probably make the building sprites myself if need be, and a lot more changes are upcoming.  This is just a little teaser.  Enjoy!
Also, this only works on the TI-83+ SE and above.  This does not work on a TI-83+ BE.  Please note that there is no restriction on going too low.  If you reach a place really deep where you just see a bunch of gobbly-gook, I would advise leaving that place to avoid crashing your calculator.
I will also be changing a few things later on, including the map generation (so that it actually makes sense ).

In the screenshot below, I show off most of what is implemented, including the digging mechanics, the smooth scrolling map, and, towards the end of the screenshot, I show a large portion of the map (by no means the whole map) to showcase its size.

Sir, this is looking fantastic! (13 pages late), really good job, some nostalgy too since I used to play this on the web when I was younger.

Glad you guys like it!  It looks a lot better on the emulator than it does on-calc, though

Sir, that's gorgeous.  Wonderful job.

By no means does it look bad on-calc (try it yourself! ), but the emulator certainly glorifies it.

I feel like you refer to the greyscale, cos it looks really nice on the screenshot.

I can't wait to try this when it's totally done!