It might be tricky if the wheels are already at the bottom of the sprite though

yeah.  Or if he wanted, he could change the on-ground sprite to have the wheels one pixel in the air, and then go and change the bounding box, but that sounds a bit excessive

modifying the sprites is anything but trivial(as i explained in my first post )
however, i'm going to be revising them as it is, so i may as well go ahead and hard code (err... hard-draw?) the difference instead of adding another special case and bogging down the engine.
thanks for the encouragement, ranman!

the level sets, gameplay, etc will be similar to the original game but not exactly the same, as some things just wouldn't be practical.
the jet fuel not being refilled by items dropped by enemies, for instance, and the map's being in smaller room chunks instead of the massive, contiguous maps of the original. i still intend to add in the overhead map portions and the bosses that need to be defeated in order to upgrade the tank, though. oh, and there will be fewer maps than are in the original game, because the sizes i'll be working with are massive enough as it is. probably just the first three (forest-y place, castle, and futuristic space station).
at the moment(after seeing squidget's sandland tilemapper), though, it's obvious that i still have some optimising to do.

Sounds cool. Good luck. Unfortunately, I don't really have too much experience with variable length arrays. Didn't your dust toy use one though?

in the dust toy i cheated and used a fixed length array into which particles were inserted at random (if the space wasn't already occupied, that is). i actually like the way that turned out, though, as it made the particle movements less uniform and more realistic.
however, after a bit of work, i think i now have a system for dealing with bullets:

there definitely won't be this many bullets on the screen at a time, but i figured: why not?

now on to the hard part: scripting enemy movements and determining when they have been struck in order to inflict damage and make bullets disappear simultaneously 

That looks great. I like the bullets too.