EJBT-AA34
Master Code (improved). Gets rid of the blank/red screen, and makes the game load faster.
Resetted the game with a number of codes still activated and got a red screen, so I got to test this after all :) Instant fix!
KBPA-EAD8
Spin attack pickup (Super Pizza) lasts 3x longer (only for Raph).
Works great! I did get stuck on the side of the screen. I tried to go to the side of the screen again the 2nd time I picked one up and it happened again. I'm not sure why it happens. It's not a big deal, though - free movement is restored when the spinning effect wears off. But I thought you should know anyway.
RHTT-C6TY
Invincibility (works on all levels)
Awesome, works great!
Thanks for the codes! :)
I have some ideas for possible codes. Please keep in mind that I don't really need these, but they might interesting to create?
#1 Friendly Fire
Apparently, there is a way for the Turtles to hit each other in 2 player mode (Japanese and European versions). GameFaqs described the cheat as "Friendly Fire". At the Konami logo press C, B, B, A, A, A, B, C. Start a 2 player game and both turtles will be able to hit each other. I heard a sound confirming that something is activated when entering the code, but I can't test it because I've never used 2 controllers with Genesis Plus GX. I could always test it with Gens or another emulator though. But I haven't been able to confirm if the cheat actually works.
#2 Level select
Level Select
At the title screen push A,B,B,C,C,C,B,A,START the level select will appear on a black screen.
#3 Always get full ending
The normal/hard modes' ending features 1 or 2 extra bits that easy mode does not get. Maybe a code to always get the full ending? Can be tested easily by using the level select and skipping to the last section, I think.
Again, these are just some ideas in case you are bored :)