Hint: Get Infinite Viewtiful Points
At any of the Power Conductor Stations (two orbs on top of small towers that light up when hit, the first you come to is in the sewers of the second episode.), stand in the middle but closer to one than the other. Zoom in and kick to hit both Towers, and the one you are closer to will light up before the other one. Kick again (while still zoomed) to finish the chain and have the towers reset. If done correctly, the conductors will not activate and the two bottom lights will be kicked on, you will also get 100 Viewtiful points for the move. Repeat this process to continually gain 100 points for as long as you want

Hint: Listen to Hidden Tune
When you're at an area with no enemies around, you can try out this neat (but useless) trick. Take out a bomb and hold the kick button (the same button used to take the bomb out). Joe will then juggle the bomb and whistle a part of the Mario theme tune. If you jump up in the air and do the same thing, and Joe will whistle a different part of the Mario tune. You have to listen closely to hear it

Hint: Skip Movies
To skip any movie during the course of the game, press Z.

Hint: Speed Up During Slow Motion
Most people may have come across this already. You can use VFX slow and VFX speed together. While using slow, you may then press the speed button and it will allow you to run considerably faster than just running normally in slow motion. Doing this doesn't use up VFX any faster either

Hint: The Absolutely, Positively Easiest Way to Defeat Fire Leo
First of all, for this method to work, you need to know Red Hot Kick (having the VFX Turbo Charger helps, too), so go down to the shop and buy them. Now, at the beginning of the battle, Mach Speed punch one of the balls of cooled lava until you have a fiery aura (you need this to be immune to the fireballs Leo shoots, as well as to break his aura). Slow kick him while you're still fired-up, then break his shield with SlowZ-RHOH (Red Hot One Hundred). Do whatever you feel like doing until he auditions for "ballerina of death of the year," at which point you continuously use two slow-mo Red Hot Kicks, and then Zoom In after the second one (Zooming in during a RHK or after the second one will make Joe do a corkscrew RHK, complete with fire), after which you zoom out and run away from Fire Leo to recharge your VFX.

A few important things to remember:
DO NOT stop using slow until you've cleared Leo's arm length. Doing so will result in damage. Wait until Joe either dodges one of the swipes or clears Leo's arm.
DO NOT do anything that will knock Leo back, including but not limited to letting Viewtiful Forever be activated. If he gets knocked back, he may stop spinning, forcing you to repeat the process.
DO NOT jump over the gap in the ring. This will have the same effect as the above. If you get to the gap, double-jump over Leo and head in the opposite direction.
If Joe loses all of his VFX, stay away from Leo until Joe transforms back.
If you're not RHKing Leo, you're running from Leo or jumping over Leo.

If you use this method, you will run a much smaller risk than using SlowZ-RHOH as your primary attack

Play as Alastor
Beat game in V-Rated Mode.

Play as Captain Blue
Beat game in Ultra V-Rated Mode

Play as Sylvia (Joe's Hottie)
Beat the game in Adult mode.

Unlock Super Mode
Earn Rainbow V rank in all levels. Start a new game and choose the same character you earned the Rainbow V ranks with and select them with Z. Super Mode gives the character unlimited FX.

Unlock Ultra V-Rated Mode
Beat game in V-Rated Mode

Unlock V-Rated Mode
Beat game in Adult Mode