A cart thing that moves automatically, similar to the one in DKC2. It has improved speed handling, uses more animation frames for going up/down slopes, as well as extra features - like slight accel and decceleration by pressing right or left.
I made a couple of optimisations in the code, at the places with the big block of compares and branches, specifically the code to set the the slope state (it had been changed to a table and also features conveyor slope compatibility) and the GFX tilemap (used to jump to the place to load a different table, now all tables are shared but the correct index is now calculated).
Other then that, the skull cart is the best you can go without resorting to patches. It's GFX heavy (taking a whole page) so it limits the amount of sprites you can use with this and you still "can"* spin jump, spin the cape, shoot fireballs, can duck and do some other actions but you can't prevent these with just the skull cart.
*"can" in quotes because the sprite reverts the spin jump to a regular jump, set the cape spin timer to zero and removes the fireballs, respectively, but the sound effects still play.
That being said, this skull cart is really an improvment over Wii's (and Carol's version if you got their version). More frames, better speed and less weirdnesses, that's all this sprite needed.