Could use an export/import function. Maybe a quick popup of what to do (i.e. click cat until mlg bar fills. Click MLG Mode On, click cat to gain gold) to start for the clueless as well. I'm of moderate intelligence and figured out how to do it within 10 seconds, but I know a lot of people who are a lot stupider than me who probably wouldn't figure it out.
Easy way to beat Rangor, use the Y axis. Stay above or below him, spam weak attacks until he moves up and gets hit, then finish the combo with a strong attack to knock him back. Repeat until he's dead.
Easy mode: Go with pure physical skills (i.e. defense, offense, agility, and speed.) Get to level 8, do the first level a few times with blind mode on. Get to level 11, do the first level a few times with Sudden Death AND blind mode on. At 15, sudden death, blind, no magic. Whenever you max all your physical skills, do the rest of the game. No one else will have a chance.
Getting all the survival badges is pretty easy- Equip the shield, big laser cannon, repair droid, decently fast legs, and the heaviest cockpit you can. Use the shield often, kill stuff, try not to get hit when shield isn't up (I ran circles around the tanks.). You should make it to wave 30 with ease, getting you the six medals for survival, +1 for killing 500 guys.