I've been playing around with the MAME debugger recently. I loaded up Tinkle Pit, a cute, simple (at first...) maze game recently and started playing around with altering memory values. I found what appeared to be the value for the current game mode, and began messing with it, and then came across an odd screen...
Interesting. The background fireworks sparkle and rotate, the characters do a little dance animation and the text scrolls up from the bottom. The text reads:
"This is as far as you can go for now in this event version! Thank you for playing!"
It's definitely not from any cutscenes, and I don't see any options for an 'event mode' in the game's service menu. Google turned up nothing as well. I can only assume by 'event' it means a trade show where the game was demoed. If anyone can provide any insight into this, I'd love to hear about it!
Playing around further with the same memory location, I found a somewhat broken level select screen. It seems that no matter what, it switches the game into flipped mode, so the screen will be upside down and the input is backwards. Plus the enemies don't seem to do anything after a level is loaded. It's still interesting, as there appear to be some test levels after the final, normal level 49. Up and down choose the levels, while left and right do.. something, but I'm not sure what.
Both of these can be accessed by adding this bit of xml to your tinklpit.xml file in the MAME cheats directory:
<cheat desc="Unused demo screen"> <script state="on"> <action>maincpu.pb@310b=50</action> </script> </cheat> <cheat desc="Broken level select screen"> <script state="on"> <action>maincpu.pb@310b=30</action> </script> </cheat>