Dark Star/02
The real final world, featuring a nice powerless section and a Star Fox-like final boss.

The part before 02 can be done with a lot of sliding, though this is not necessary. Some people like to puff the last N-Z enemy, but I like to inhale it because the camera angle there is terrible.

02 is a fairly straightforward boss with RNG that can managed without losing (significant amounts of) time. Each cycle of the fight proceeds in three steps. In the first step, shoot the eye 30 times while 02 shoots back. For VC, you can slightly tilt the control stick to the bottom left to avoid 02's shots. For N64 (and an alternative strat for VC), you can repeatedly tap down and left. Afterwards, shoot the halo 10 times and the bandaid once. Once that's been damaged, 02 reveals a green spike. Hitting the spike is the part that actually reduces its health meter.

Ribbon's shard gun (apparently that's the official name) shoots out four crystals at a time, each of which has its own cooldown timer, so sometimes they'll fire at irregular intervals even when mashing the B button. Overall, the irregularities don't make too much of a difference.