Tip for badges: Use 4 Homing, Energy Homers and Lightning to go all the way to the boss level. Mainly use 4 Homing and Energy Homer to kill the enemies and in emergency, like enemies surrounding you, use the Lightning. For the last level, go inside the boss, use Lightning then use Duck Death and finish off with Energy Homer. Anyways, level 58 was the only level that pisses me off :)
Tip for medium: Buy the FN SCar, Hollow Points, Extended Magazine and use the rest of the EXP for Maximum Base HP +25. The FN Scar is a really good gun because it got a beast damage and fast reload speed :)
Easiest way to earn the medium badge:
Get 2 brutes and 1 ranged person. Make sure one of your brutes has a weapon that breaks enemy's weapon and your other brute should just have a good melee weapon. Equip your ranged person with a gun that shoots when he/she is idling and make sure you have a weapon that bounces when shoot. Make sure your brutes has health perks and more melee damage while your ranged is totally up to you but make sure they have more shooting damage. In battles, get your brutes to come forward and attack the family. When that brute die, get your other brute and finish the family off. If for some reason, all your brutes died, just use your ranged person and finish them off.
Play it long enough and it will be easier for you to get the hard badge. I got mine after 2 hours of work. Don't rage too much, it will make things more complicated.
 "Heavy Weapons"){kind=icon}
 "The Endless Zombie Rampage"){kind=icon}
 "Balance Balls 2"){kind=icon}
 "Boss Slayer"){kind=icon}
 "Chuck the Sheep"){kind=icon}
 "Billy the Pilot"){kind=icon}
 "This is the Only Level"){kind=icon}
 "Sonny"){kind=icon}
 "Deadly Neighbors 2"){kind=icon}
 "Deadly Neighbours"){kind=icon}
 "Burrito Bison"){kind=icon}
 "Ninja Hamsters vs Robots"){kind=icon}
 "Monster Slayers"){kind=icon}
 "Apokalyx"){kind=icon}
 "Topsy Turvy"){kind=icon}
 "The Programmer RPG"){kind=icon}
 "Balloon in a Wasteland"){kind=icon}
 "ESCAPE"){kind=icon}
 "Mardi Gras Mayhem"){kind=icon}