• Laser: The attack you can perform by holding the attack button. Generally it has high power, but your character's movement speed will slow down.
  
• Shot: The attack you can perform by hitting the attack button periodically. Generally it has less power, but you can move fast.
  
• Targeting Magic: The attack you can perform by pressing the both side of attack button. It depends on your character, but basically it attacks the nearest enemy.

• Normal: Vanilla.
  
• MBL: Something like DLC. It adds a new playable character, new optional stage, crazy difficulty Lv999 choice, buff on some playable characters, major changes on score calculation systems.
  
• Arcade, MBL Arcade: Low-resolution version of the each. You don't need to choose this.
  
• Ver 1.1, MBL Ver 1.1: Another arranged game system. You can be "power up"ed mode much longer, but enemies' attack also become much difficult.

For the first play, I recommend MBL mode. Your character is stronger than Normal mode, though the enemies' attack are not too difficult.

Rosa. She has the strongest firepower, which means you can kill the boss before his final critical attack comes.
Follet and Windia are moderate. Casper is... yes, she's so cute and everyone choose her, and...

The new character, Sakura is the strongest.
Follet and Windia got much stronger, and now they have almost as same firepower as Rosa.
Casper also got enhanced, but she's still the most difficult to use character and I do not recommend to use her.

This is verrrry complicated part of this game. I can explain it in very very long way, but I summarize it for you.
Even you're not interested in the leader board, you still need to know how to earn scores. Because if you reached a certain score (you can check it in the title screen) then you can get +2 lives at maximum.

Some enemies drops items to increse the power-up gauge. There's 3 types of the items: Skull, small crown, large crown. When the item drops on the ground, it "break up" into 2 low-level items. Generally, this is a loss of score.

Every enemies who possibly drop items has a property "weakness shot". When you killed that enemy by that weakness shot, then you can get one more high-level item than usual.
Generally, soft enemies' (like eyeballs, blue phantoms, ) weakness is shot, and hard enemies' (like hounds, cyclopses, dragons) weakness are laser or targetting shot. You need to know this to reach power up mode as fast as possible.

It's simple. Kill the enemies by their weakness shot, and:

• (non-MBL): get close to collect items before those drop onto the ground.
  
• (MBL): wait for the items drop on the ground and split into skullls then collect those.

Then the story changes (for non-MBL guys). While you're power uping, dividing the items earn more score than getting those immediately.

When you trigger power up, all the purple bullets in the screen turns into a gold crown. So you may want to stop shooting for a while before power-uping to let enemies shoot more bullets. The well-known good place to do this are:

• Graveyard's hound dog just before the large house
  
• Swamp's large cyclopse
  
• (Only for non-MBL mode) Each stage's bosses' attack

This is the best place to earn the score. You'll need to get ready to power-up in the previous stage. In this stage, there's several holes that is throwing tens of rocks away. Power up and stay in front of that hole, and keep shooting to that hole. You can get hundreds of skulls and your score will bump up.

Except Normal mode, you can choose level 1 and level 2 once in each verse (so you can choose 2 level 1 stages, 2 level 2 stages, and 2 level 3 stages). Also, if you choose level 3 stage more than 5 times, you enter the "death mode" which is more difficult than level 3.

• Port town: Very easy even in level 3. But there's very few enemies drops items, so you may cannot earn much score.
  
• Forest: It is difficult in level 3, especially the boss'es last attack is almost impossible to avoid unless using the bomb. But instead many enemies drops items, so easy to power up.
  
• Lake Shore: Not much different in each levels. The boss is weak also.
  
• Graveyard: Not much different in each levels too. But the boss'es level 3 attack is bit difficult (esp. in non-MBL mode).
  
• Swamp: Level 3 is a bit difficult. Considering the life recovering item (I describe it below), choosing level 2 is a good choice I think.
  
• Volcano: Definitely choose level 3 for the scoring. Yes, it's bit difficult so do not hesitate to use the bombs.

Under certain chapter and level and stage, you can get life recovery item or bomb item in the stage. Here's the conditions:

• Small item (recovers 1/2 life): Level 2 swamp in chp. 2 or 3, level 3 graveyard or volcano in chp. 3, Death mode level 3 port town.
  
• Medium item (recovers 1 life): Level3 volcano in chp. 3.
  
• Bomb item: Level 3 swamp in chp. 2 and 3, Level 3 graveyard in chp. 3
  
• Large item (recovers 2 life): Defeat father in the last stage without using a bomb while fighting against him.

So I think the easiest & max life recovery item route is this:
Lv1 Forest ==> Lv1 Graveyard ==> Lv2 Lake shore ==> Lv2 Swamp ==> Lv3 Port town ==> Lv3 Volcano.