Gospel duplication cheat:
First off, this cheat will only work if you can go to kotobuki via the train. First SAVE before getting any purple or blue mystery datas. DONT SAVE AFTER YOU GET THE DATA! otherwise you wont duplicate it. After you beat gospel and let the credits role, continue playing. This cheat will work on any mystery data except power ups (i.e. hp memories, reg. ups, power ups ect.) This means you can get as many recv. 300s that you want (same with: anti navi, navi+40, ect.) You can even duplicate zennys. If you find the 50,000 zenny mystery data in undernet 5, you can duplicate that as well.
(supplied by: analogman101)
Hard mode:
Beat the game with all five stars. Highlight New Game at the title screen and press Left, Left, Right, Left, Right, Left, Right, Right. Save the game and restart to get a Hard Mode option.
