I wish the berserk is triggered by some keyboard key instead of double mouse click, I mistakenly triggered it several times when changing shooting direction.
What's the point of banking in survive mode? This option should let you save your trophies and kill/gem counts at the cost of your current score. But it actually neither save trophies nor save counts, if you die you lost everything, the only use of it is lost some score and move 2 floors up, lol?
7:35 died twice :D  It's not very hard to beat in 8 minutes, you just need to memorize where the items are. Don't rush too fast, be patient to deal with enemies, the time is just abundant if you don't die and don't go wrong ways.
The key to beat the game is to find out where you must place a door or goldbag first. For example, in bonus stage 1 you must place a goldbag beside the gem to lure yourself to get the gem, and you must place a door beside the goldbag otherwise you cannot leave. If you can find those key places the game will be more easier.
OH I FOUND HOW TO BEAT LV 14 NINJA BOSS: Build crypts near your gems, DO NOT build them on the highground or near the enemy entrance, make sure they upgraded to fear before boss. When wave 49 ended, remove all towers except crypts, the ninja will rush to your gems, and your crypts will attack him. If he get feared, he will run back to the entrance and waste his cloak time. When he calm down and go to your gems, his cloak is end, your crypts will rape him.