If you're just after the badge focus on magic use for the energy hero and just boost her, pure energy will get you by on most levels. Extra lives is a must on some levels though.
got the hard badge using the link197840 method, pause and unpause constantly. one thing to note, you don't have time to wait to see if you hit, you need to spam the balls.
hooly, just got lvl 70!! Your best bet is if you get couple of ricochet areas nearing the end, and to get that you have to be reaaaally lucky, the drop rate for the ricochets is the worst of the 2 buffs, (the curve ball is a debuff)
ok tips for the hard badge, turn off all the effects and just follow the perimeter and shoot towards the center, try to stay relaxed and don't tense up.
Fun game, the randomness of battles is very annoying though, sometimes when losing I'd reload and manage to beat the same foes the second try because maybe the team would focus their attacks on a single foe and annihilate them that way whereas they would just run around and do nothing in the other fight.
Started by upgrading two ion towers to max, they were plenty powerful to prevent population decrease even though I didn't upgrade the bunkers. wasn't until I had 5-7 fully upgraded ion towers that I started researching the missile towers.
Finally got apocalypse, chess board pattern bunkers and towers seems to work best for me. I needed 6 economic centers to have enough money for the upgrades. I ended up with 5-7 fully upgraded ion towers at the front which made quick work of the smaller ships, at then end the last row was all missile towers apart from two missile defenders.
if you really want the badge but can't be bothered to type load up this script in autohotkey(within the "'s)
"SetKeyDelay, 0
F1::
Send abcdefghijklmnopqrstuvwxyz"
F1 sends the alphabet, you need to click it a couple of times for some words, game started lagging a lot after 1-2 minutes so I couldn't ever get higher than 20x combo with it.
WHEW, finally managed to beat Stream on hard. You definitely need banana farms, when you have three tier 3 it makes sense to sell two and get a tier 4 farm you will make 500 more bananas. banana farms seem to be non-optional since you don't make much more money during the later waves.
 "Talesworth Arena: Death Watch"){kind=icon}
 "Protector IV.V"){kind=icon}
 "Magic Quest: TCG"){kind=icon}
 "LightSprites"){kind=icon}
 "Areas"){kind=icon}
 "Cubito Mayhem"){kind=icon}
 "Wondrous Lands"){kind=icon}
 "PlanetDefender"){kind=icon}
 "Mushroom Revolution"){kind=icon}
 "Typing Ninja Hunter"){kind=icon}
 "Warlords: Heroes"){kind=icon}
 "Bloons Tower Defense 4"){kind=icon}
 "5 Step Steve"){kind=icon}
 "Magirune"){kind=icon}
 "Kingdom Rush Frontiers"){kind=icon}
Thank you for the feedback!