The hook launch delay is really annoying, I found hard to feel where it would land so I had to play each jump slowly. It would be better if it targets the spot selected at the moment of launching instead of just following the direction, since the screen scrolling is too fast.
It seems that unlocking a weapon also unlocks an enemy of the same type. Flamethrower is OP in enemies because of the effect. What a bad design choice.
FOR ANYONE LOOKING FOR EXTRA LEVELS: Use the arrows in the bottom to scroll in the different challenge modes. Weirdly, it starts in the last empty page.
The fastest way to level up is to hit all the tombstones at the same time. Reset until they get together. Doing this, I finished the game in less than 3 minutes.
 "Idle Zoo"){kind=icon}
 "Rule of War"){kind=icon}
 "Vinterget"){kind=icon}
 "Tanks Of The Galaxy"){kind=icon}
 "Pixoji"){kind=icon}
 "Portal: The Flash Version"){kind=icon}
 "Monster Bark"){kind=icon}
 "Bloody Fun Day"){kind=icon}
 "Axon"){kind=icon}
 "4 Differences"){kind=icon}
 "Cosmic Clicks"){kind=icon}
 "Strike Force Heroes 2"){kind=icon}
 "SAS: Zombie Assault 3"){kind=icon}
 "i saw her standing there"){kind=icon}
 "Gibbets 3"){kind=icon}
 "Typing Ninja Hunter"){kind=icon}
 "Super Marine"){kind=icon}
 "Castle Crashing \"The Beard\""){kind=icon}
 "Road of the Dead"){kind=icon}
- Use [ ] – square like symbol in the upper right corner of the screen to enable fullscreen mode.