Boost over to Misery holding X to charge the Spur. Should be at about 3 seconds when you reach her. Release X and get through the convo, when it ends, Spur will fire and glance her, then go under and spam her until she teles. Charge your spur, then fire when you're under her and spam fire up until she teles. Repeat until defeated. Should be at about 30 seconds. (I'm always at about 25.)
Boosts over to the doctor with Spur charged. Same starting tactic, release X after convo, then switch to blade and charge into him (completely ignoring his attack) and spam upward with Blade (now level 2) and Nemesis. You can get him down after the first tele, unless he goes across the screen and you can't get to him in time. After 1st form is down, just spam up again against the second form. Stand on the side of him closest to the exit, because he will probably push you towards that direction when he pounces. Second form should take all of three seconds. (Not kidding.) With blade equipped, go to Ballos.
Ballos' first form, just walk into him and spam up with Blade. Touching him normally will do 3 damage to you, but him stomping will do 10, so be wary of that. After that, when his second form is spawning, go as far right on the map as possible, and equip your rocket. When the ball drops (ha) jump up into his eye (you can stand next to it) and spam your rockets. Unless you're a lefthanded trigger finger, you won't kill him before he starts falling again, making you fall off the eye. Hold the down arrow this entire time so when you fly in the air and fall off, you're still aimed at his eye. You should get him before he finishes the second bounce. Entering the third form, equip either your Spur (for the instant kill of 2 balls or so), Blade, or Nemesis. (Prefferabley the Nemesis if you got it. Longer range.) Stand on the left side of Ballos as he's spawning the balls around him. Stand where if you fire straight up, you'll hit two of the balls. (Not under Ballos, but on his side.) Spam your weapon upward to kill most of the balls, then when he's going up the wall, switch to rockets and spam those until you're out. Do whatever you want to get rid of the remaining balls. (Spur up, Nemesis, Blade, whatever. Only a true speedrunner can beat this form without having it go around a second time.) When the final form is spawning, go ahead and use your Cure All and Power Gauge (if you need to use the Cure All sooner go ahead, but save the Power Gauge until now.) Switch to your spur and stand on the floor. When the spikes hit you, switch to your Rocket launcher, and boost up towards the eye safespot I talked about earlier. (It's a little tricky to get into, but simple enough.) Now spam your rockets and he will go down in about a second. (If you didn't get the missile upgrade then shame on you.)