DK barrels, but SM.

Can adjust x/y speeds independently. Speedboost on by default, easy enough to comment out. At least 2 barrels full of jank in there. Code and comment quality varies.

rar contains .asm, .gfx, .tpl, and .xml for use with SMART.

I highly recommend using speedkeep and respin with this enemy.

some known jank
Samus doesn't always load smoothy
Samus cannot enter the cannon with iframes
Samus doesn't move perfectly in sync with a moving cannon
Samus' max fall speed had to be increased, or a cannon arc turned into a line very quickly.
Samus loses all upward momentum if you release the fire button (jump by default)
Item selection is very messed up while in a cannon
Unpausing in a cannon starts the spinjump sfx
Speedboosting sfx do not play
Shooting a cannon straight down can surpass the fall speed cap.
Shooting a cannon straight down close to the ground may cause Samus bounce instead of breaking blocks.
Grapple beam