For those trying the hard badge, remember to, beside following harrvestsun sugestion, ALWAYS move on the oposite way of the incoming ships. It is a a lot easier to cross the fire line than outrun it. However, remember that there is a acceleration time that you must account for.
Also, if you position yourself in an almost vertical position, you can shot a very focused stream of bulets - very useful to give massive damage to ships on your same line.
You all do know you can ignore the kreds part and play the game without any problem at all, right? If you like it that much, then buy the new things. Otherwise, ignore them and be happy.
Cool trick: Jump and sleep at the same time. You will end up in an invisible platform. After a while, you will be too high for the enemies to reach, and they will simply sit around under you getting killed by fort towers.
Way too similar to Desktop Tower Defense. The Different map shapes, however, make up for it.
BTW, loved lv 40 xD. Very original and unlike other tower defense levels.
Ridiculous, bug ridden, badly designed levels, Extremely unexplored genre, too similar to hundreds of other similar physics games... Should I go on? This game is a disaster!