Why is this game rated with a 4.3? No question it is not bad, but way too short and too easy. Compared to other complex games, this rating is not fair.
Currently i need 570 pieces for the merchants orders, this number increases for 10 more pieces from time to time. do you know on what these numbers depends? Lvl, total number of accomplished orders, harvest speed,....?
For the impossible badge:
1. always stay in one corner (because mobs will not spawn from all directions this way).
2. if you are low on health, wait for the big blues or big reds and dont kill them. just circle around them and wait until your health is full (you will kill the small blues coming out the of the big, while circling). if you dont kill them, no new mobs will spawn.
3. use shockwave for the small mobs (the best use is to go in the center of the screen). deathray for big blues, and shields for big reds and blues. (also for huge numbers of mobs on one place)
4. if there are much shooter monsters out there, use bullet time to escape the bullets without much damage.
5. strg plus + for a larger screen. click strg and + beside the gamescreen.
imo the imp badge is more a hard badge. if you follow these advices, you will not need more than 10 tries. good luck :)
the blue key is near the second checkpoint. you have to use the rocket to get there (above the 2nd checkpoint) (the second checkpoint is where you get the double jump)
for the Maxing Multiplier Badge you have to evade as much enemys as you can, avoid fire and get high to get the dragon ride. in dragon mode you can easily raise your multiplier for 5-10. and of course you need luck :)