A couple more pointers:
1. Like justinian78 and breach said, give first upgrade priority to fuel, hull, and nitro. I would add drilling to that list, because fuel means nothing if you aren't plowing through that dirt.
2. Aim to get the trophies, especially the depth ones as, if you get them all, they will provide you with a $100,000+ bonus at the end. Go to the trophy room if you want specific details on the worth of each.
3. Big diamonds give you lots of money. When you've maxed fuel, hull, nitro, use one or two boosts to get down to where the big diamonds are. Use the mole (prefer level 4 mole) to grab even more. Use the rest of your boosts to push through areas where you can't see or grab anything.
+ if this helps.
I have failed many times now in trying to accumulate a great number of points. And for some peculiar reason I keep trying. I think the 16th-note shredding on the guitar is the game's problem/sauce. 5/5!
This game ought to get a Game of the Year award for novel concept and strategic play! This is, hands down, one of the most simultaneously simple and brilliant games.
I think my wearing headphones and hearing the heavy, raspy breathing in the background of Inferno mode is what's making the shapes fall over.. -__- I know. I know. I keep hearing the same thing, and I should be used to it by now...
The nature of the "paddle" doesn't lend itself very well to the dynamics of World 3. The reaction time is too slow to change direction. Despite these two things, the game is incredibly addicting!! I love World 5!!
This game feels eerily comparable to the "Robot Wants ___" games. However, RBK and its sequel games don't have a plot such as this one, much less optional story endings. This game kicked so much butt!