Get reactions to 600 and speed to 800 (They are the fastest to train), buy the best items and you'll win the premier league (stamina was 300, agility was 400 - avoid races with obstacles). Keep health at 80+.
I had the unfortunate displeasure of earning the Hard badge on this game. To beat the final boss you need to spend about 2 hours grinding, and then 1-2 more hours doing boss attempts (more if flash player crashes and it doesn't save your game). The boss's behavior is random. When he gets below about 25% he goes berzerk and casts spells which do more damage. Grind for all the upgrades on your mercs and go into the final boss fight with full runes every time.
Eventually you'll get lucky and he wont spawn any mobs until he's at 25%. Burn him down and kite his minions. Once he's at 5-10%, focus fire him down, his shield appeared to melt faster when he was low. There's no strategy here, just luck.
One thing to note is that his minions block his fireballs, which can prevent you from dying. Also note that you're invincible in whirlwind mode, so use that to get close and deal damage to the boss. This balance in this game is atrocious 1/5.
if i go far enough and fast enough to the left, i should eventually enter orbit... Also, rockets should always accelerate you, here they just bring you to a maximum speed, even in space w/ basically no resistance
I used the boss portal (H) on level 25 and once I beat the boss level it said I beat level 25. The boss level was actually really easy though, much easier than fighting Epic (the last boss of the real level 25)
CAMPAIGN: buy uzi, buy 1 gunner(g), buy flamer(f) in position 3, buy shotty for trucks, buy (f) in pos. 1, invesnt in (g), sell flamers when u can, at lvl 17 upgrade wall once, at 19 get a shield gen, buy 5 repair men, at 25 buy a shield gen (max upgrade both), upgrade wall once, buy space lazer with 3 ammo (sl), buy 10 (r), buy lazer tower (lt). By level 30 you should have 110(g)/23(r). Max the (sl) (radius too) and the (lt), max the wall, and then pour all your money into (r). IF THIS WORKS FOR U, PASS IT FORWARD
If The strat I mentioned works for you, please pass it forward, since I know alot of people are having trouble with the campaign, and there are few (if any) reliable ones posted in these comments
If you are having trouble with any of the campaign levels, I recorded down the total amount of money you could expect to have at each level, so go into sandbox and try out different strategies.
level 2: 920, 3: 2240, 4: 4020, 5:6020, 6:8040, 7:10629, 8: 14370, 9: 18810, 10: 24820, 11: 31800, 12: 40170, 13: 48750, 14: 59550, 15: 71270, 16: 85110, 17: 102720
At end of day 40 i had 64 (r) and 122(g), but i don't think i needed that many (g), since the space lazer has a huge radius, and can take care of all the tanks.
SOME TIPS: At the start, you'll have to buy healthpacks when necessary. Its very possible to get the second flamer in this strat in the order i mention, but it will be close. Use your uzi to fire single shots into the clouds constantly, you can stop 100% of the planes this way.
CAMPAIGN: buy uzi, buy 1 gunner(g), buy flamer(f) in position 3, buy shotty for trucks, buy (f) in pos. 1, invesnt in (g), sell flamers when u can, at lvl 17 upgrade wall once, at 19 get a shield gen, buy 5 repair men, at 25 buy a shield gen (max upgrade both), upgrade wall once, buy space lazer with 3 ammo (sl), buy 10 (r), buy lazer tower (lt). By level 30 you should have 110(g)/23(r). Max the (sl) (radius too) and the (lt), max the wall, and then pour all your money into (r). IF THIS WORKS FOR U, PASS IT FORWARD
For those of you trying to do campaign, start at level 1 in the sandbox, then invest money in your UZI until you die at like level 7 or 8. Then restart the sandbox at level 7 or 8 where you left off, setting your total starting money to where it was when you died (which can be figured out by starting with like 100k and then spending to where you were when you died... the difference is how much you had to begin with). Find a strategy which gets you further and further through the levels, restarting as necessary.