To get a better view and control of your mech while it fights, use your Gravity Boost (on the "Hero mode", hold Circle) and boost your way to the top of a nearby building. You can now get a much better view of your mech and the fight that it is in.
Catch The Jammer In Rat Race Easy
In the level: Rat Race, there is a jammer you have to destroy, but it's in a truck that keeps driving to different parts of the city. Even if your speed is maxed, it's still a pain. So, when it stops at the supermarket, jump in the back of the truck, and stay there until you get to the school area. Then blow it up. This way, once you are in the truck, you can control your Meganite, so it doesn't take as much damage from battle.
Completion bonus
Successfully complete the game to unlock all robots in versus mode.
Faster intermission sequences
Hold Start during an intermission sequence to fast forward it.
How To Get More Robots In Two Player Mode
First you should have a memory card if you want to save this. Then play one player mode and get to the third fight you should find a green guy that is attacking town. Kill the green guy and you get him in two player mode. There are various types of robots in future levels you can earn.
Superior Vavel
As soon as you start getting money from killing Volgara, try to put as much as possible into making your character and Vavel more powerful by purchasing new attacks, thicker armor, and more ammunition for your weapons. Vavel's power is average at the start of the game, but if you build it up completely, it will be combat superior to all of the other enemies and Meganites, including Osmodeous.
Vavel's Volcanic mode
Vavel's Volcanic mode has the ability will allow you twice as much power in the normal mode. This can be very helpful if you are losing a fight. If you are not very skilled at controlling Vavel yet, you should only use it as a last resort. If you start off in volcanic mode and cannot control Vavel well enough, you may run out of time and lose the fight. This is also the same with Vavel's Genesis mode, only you gain about four times normal power.