Alternate strategy for level 14: eat the first bat and slam down right as you get to the 2nd bat in the line (the timing is VERY tight). You will jump off the 2nd bat and be able to jump off another to get to the skull totem. Ride the nearby bat to the west.
These games are always 5/5 for me. I particularly enjoyed the difficulty ramp in this one. Requires you to think outside of the box, but isn't too difficult at the same time.
The stragehy behind the deck that will break the damage meter is to use Sketching to duplicate a ton of the following cards: Muse(30+), Apple Pie(20+), Baking(10+), Curiosity/Inspiration(30+ combined), Sketching (10+), and Gore (10+) (careful not to get too many of these too soon). Only use the Red ability until you get one Big Guy, then you will only be using the Green ability to reset your hand. Once you get a large enough percentage of the core deck, you will restore more energy than you spend resetting your hands, allowing you to stack Gore as long as you want.
reload speed and vision radius seem to be very important for evading spitters in Endurance. A weapon with 2+ spread upgrades, pen, and quick attack rate clears waves easily.
If you make it to the challenge levels and find yourself scratching your head with a few 50/50 situations, I find it's easiest to make note of where you are and try one option out. If it ends up failing, use the undo button until you get back to the original 50/50 and try the other. Helped me a lot with the medium challenge levels.
 "NABOKI"){kind=icon}
 "Greedy Mimic"){kind=icon}
 "Elephant Rave HD"){kind=icon}
 "Choppy Orc"){kind=icon}
 "Flood Fill"){kind=icon}
 "Aisleen"){kind=icon}
 "red"){kind=icon}
 "Balls vs Zombies"){kind=icon}
 "PicRoad - Pixel art puzzle"){kind=icon}
 "Reaper of the Undead"){kind=icon}
 "Pixoji"){kind=icon}
 "Sort the Court!"){kind=icon}
 "Exit/Corners"){kind=icon}
 "Flies"){kind=icon}
 "Tesla8"){kind=icon}
 "GeoSketch"){kind=icon}
 "Gateway I"){kind=icon}
 "Bloons Super Monkey 2"){kind=icon}
 "Bit Battles"){kind=icon}
If you're getting motion sick, try turning on "Lock Camera" in the options menu.