Very steep curve on heroic. Gets much easier once you clear the first and each subsequent area allowing you to revisit the bosses for additional exp/loot/money. That first area is a doozy as psychological. Much easier as bio
Candy Drill: Save plasma award from reaching the core to purchase jump then alternate between red planet and green planet when you need gems or materials. Purchase the H5 Hornet next and try to max it, you can use it to do all red achievements except powerful red (500m 30s), and it gives you achievement reward of 1000 plasma to max other stuff. Max the wasp hull for powerful red achievement with the b5 nova battery turbo charge feature boost all the way pick up speed buff if they are right next to you. For Durable and Energetic just lock your steering to the right or left using the hornet or your biggest hull with your fattest battery and go afk or open another window and surf. To be honest alot of this is grinding materials/technologies so return to green boost down to 500m or so lock the steering horizontally and afk. >.>
Ending 5. Ignore collectors trophies focus upgrades (primarily drill, hull, fuel) getting as deep as you can to the big diamonds, an occasional nitro, steering and radar upgrade will help you along the way. With 7 weeks, hopefully sooner, you should have maxed everything except maybe steering, so get down to around 2000 feet right along the final change in earth density then strafe laterally and farm those diamonds with the mech mole for the final weeks. You should make at least 30k per dive and the connoisseur badge while you're at it. Save your nitros while you dig, try to keep vertical dodging the occasional rock. Constantly send out the mole, prioritize the highest value treasure in the area or send it along a line that hits multiple caches. Good luck!
Game is hard on this crappy work PC. every time i click it freezes. In any case if it's as smooth as it plays in these youtube videos its a piece of cake. Establish a solid 3 tower defense to open and sparing use of monkey glue on yellows and pinks while you hoard up to buy your first banana farm at round10 or 11 and focus on upgrading them as well as establishing others to carry you late game when the round rewards are simply not enough to get the necessary final forms for your towers. You must also know the waves that hit you hard, like the first iron balloon wave, the mass camo balloon wave, the mass rainbow wave, ceramic wave and your first moab wave. Invest in the necessary final form towers to combat those respective 'doom' waves right before they hit. It's possible to win on hard with 4 farms on their second to last form as long as you don't lag as hard as i do and can grease the lanes liberally.
A feature to turn off certain effects, in particular, the rain and fire on the last level. I'd be done already if the frame rate didn't drop. It's a crap PC, but it passes the time.