I didn't have a problem with the + shaped puzzle, it worked properly for me. I don't see what everyone is complaining about, either that, or I got really lucky.
I have no problem with hard games, but you should at least lead up to it. The first two levels were super easy, then on the third level, it jumped up from super easy to hard.
On the level where there floor falls out beneath you, I was curious... So I jumped and made it to the spot where the end of level sign is... But it's fake. :/ Worth a try though. ^^
For the Endless Tower... I suggest using your leftover AP at the end of each battle for extra exp. Just stay right by the exit, and try and make the biggest buildup you can, then drill it with 1 AP left and exit the stage.
 "Accelerator"){kind=icon}
 "K.O.L.M."){kind=icon}
 "Coinbox Hero"){kind=icon}
 "Zombotron 2"){kind=icon}
 "Paladog"){kind=icon}
 "Catch A Crab 2"){kind=icon}
 "The Adventures of Red"){kind=icon}
 "Artificial Junk"){kind=icon}
 "Edmus"){kind=icon}
 "Death Worm"){kind=icon}
 "Upgrade Complete 2"){kind=icon}
 "I Have 1 Day"){kind=icon}
 "The Legend of the Golden Robot"){kind=icon}
 "Hack Slash Crawl"){kind=icon}
 "Reckless Speed"){kind=icon}
 "Knightfall 2"){kind=icon}
 "Sierra 7"){kind=icon}