In Sengoku, you can throw fireballs by pressing and holding the Attack button when standing still for about 3 seconds. When your character's wrist starts flashing light blue and is holding a blue ball, release Attack to fire. You cannot do this while moving or if you have swords equipped.
This is a bug/glitch caused by how the Checkpoint system works in Neo Turf Masters, but you can use it to your advantage on the Hard & Insane difficulty levels: Normally you have a limited number of Rest Points on these levels and, if you don't play well, you can run out before you finish all 18 holes and if that happens the game is over. However, if you quit or restart the game and resume from your last Checkpoint (in Neo Turf Masters Checkpoints are created after each hole finished, not at the Game Over screen) you will restart with the normal amount of Rest Points you should start a new game with! So by exploiting this glitch it's possible to complete an entire round without running out of Rest Points no matter how bad your score is!
This is a possible glitch/bug that only works on games with Goals of "Beat Game On Hard" and/or "Beat Game On Insane" (should be all games except Shock Troopers): If you start playing a game on the Easy or Normal difficulty levels, stop playing after a Checkpoint is created (usually at Game Over screen), return to the Main Menu and change the game's Difficulty to Hard or Insane, then return to the game later via the "Start From Checkpoint" option and finish the game, your initial settings won't change but the game may recognize it as finishing the game on Hard or Insane and thus award you the corresponding Hard or Insane medal instead!
To unlock the hidden game "World Heroes", earn 10 medals.