That awkward moment when the badge is asking for 50,000, and when you finally earn it you've accidentally skipped 50,000 and gone straight for 500,000...
To add on to what Killernico16 was saying, I'd suggest making Shadow Cloak last indefinitely (until you're hit) if you go through with that. His post is six down from this one; I highly recommend reading it.
Add more diversity. More levels (the three you have are great for an endless runner), more characters (with more to them than 'lol this one has bouncy boobs and this one has a scroll on his back'), more en-- Well, maybe just bosses.
Also, if you're going to do a mutliplyer limit AND a ridiculously small amount of cash, make it so the multiplyer works on the amount of cash you earn.
Lokritz, jump when the beam isn't there, grab the key, then pause before you hit the beam. The ninja will be frozen, but the beam will keep flashing. Time it right and you can just fall through.
Tolga, that's supposed to happen so that you don't end up spending the next five minutes firing your accelerator into a wall you can't break. The game itself was somewhat entertaining. The ending was funny. Unfortunately, the mechanics have been done about a billion times already, and they weren't really that great the first thirty times anyway.
Semi pro-tip: If you're going for a hi-score (why are you even still playing this if you aren't?), don't look at the score. Don't even look at the chat-box until you crash. And don't focus too hard. Just relax and let your hand/finger (I wouldn't recommend using a chat-box with this, but to each his own) move smoothly. Jerky movements are your enemies.
This game is pretty fun. You know what isn't fun? Standing in the exact same place for half an hour, watching an unfriendly Ax Family Cleric freeze you in place for hours on end while autohealing any damage your immortal ally manages to deal him.
Deltian, the first three things you said aren't true, and the last two are you complaining about the game's difficulty. I think I found someone who ended up hitting the give up button...
Elsana, TV Tropes is made up of references to other things. You know that, right? It is literally impossible for anything to be a reference to TV Tropes, because the titles of the tropes on that website are all references.
This is surprisingly deep for a Pong game. The ninja's ninja-toss ability is great for knocking Raise Dead spells back into the enemy's health. Shame there's no multiplayer...
 "Ninja Slash"){kind=icon}
 "Never Awake Dev Build 1.0.1.1"){kind=icon}
 "ButtonX20"){kind=icon}
 "Bear Grills"){kind=icon}
 "Accelerator"){kind=icon}
 "Hands of War 3"){kind=icon}
 "OVNI"){kind=icon}
 "Zombie Slayer"){kind=icon}
 "Class 3 Outbreak"){kind=icon}
 "Give Up"){kind=icon}
 "Fear Less!"){kind=icon}
 "UFOwned"){kind=icon}
 "Soul Tax"){kind=icon}
 "Pong Fantasy Quest"){kind=icon}
Close your eyes and use the force!