Possibly two of the worse things about Endless Mode are the luck-based missions that require you to pick up X amount of items, and the mines appearing directly under you and detonating.
In order to win a battle in Multiplayer, you must both A) Beat the boss without running out of time twice, and B) don't die. This is why you still lose if you win twice and die.
The boss feels incredibly luck-based, since you have to hope for red worms in order to damage the cannons. Combined with you being forced around by meteor impacts and the randomness of meteor shots, the boss feels like it's running on fake difficulty due to the luck element present.
Occasionally, you are unable to reach coins, making it even more irritating than it should be just because there are a few coins beyond your maximum walking distance.
I have a bug to report. I assigned some to worship, and I somehow managed to make it impossible for me to gain any more upgrade points, excepting Nomads.
For those having trouble with the Violence Abolisher (the axe boss), he throws an axe at the bottom space, then throws axes from the top down twice before taking a break. You can also move into axes when they hit the ground, which also works for the axe mooks.
 "Learn to Fly 3"){kind=icon}
 "Idle Button Mash"){kind=icon}
 "Running Fred"){kind=icon}
 "Endless Boss Fight"){kind=icon}
 "Max Damage 2"){kind=icon}
 "How Dare You"){kind=icon}
 "Notebook Space Wars 2"){kind=icon}
 "Escape from Zombie Planet (alpha)"){kind=icon}
 "Epic Battle Fantasy 4"){kind=icon}
 "Imperfection : Prototype"){kind=icon}
 "Kingdom Rush :Flash Version"){kind=icon}
 "Don't Move"){kind=icon}
 "Cursed Treasure 2"){kind=icon}
 "Platform Shooter concept"){kind=icon}
 "Pre-Civilization: Stone Age"){kind=icon}
 "The Peacekeeper"){kind=icon}
 "Dawn of the Dragons"){kind=icon}
 "Brick-Force"){kind=icon}
That.... that is sounds like something I have to fix asap....