I'm really glad to see another new working LD game in MAME. I noticed when you go to the trader to buy time reversal cubes, even if you have the cube limit set in the dip switches, you can spam the coin button and get a ton of them. Is this just how the game is or maybe a bug?
Btw, if you look in the ROM with a hex editor, you'll find a ton of C compiler related strings.