Time your shooting of the fairies and bubbles to have maximum impact on level 1 obstacles. Destroying level 1 bullets this way will lengthen your Combo, put all those bullets on the opponent's screen, reduce the number of obstacles you have to dodge, give you Bpoints and increase your spell bar. For Lily and some special attacks, strategic destruction of fairies and spirits can be critical to surviving the encounter, as they reduce the number of obstacles your character will have to weave past.
Keep calm. More damage may be done if you rush around. Keep your movements economical and minimal. Sometimes sitting still can save lives.
If you are fairly confident in avoiding collisions, always try to shoot the enemy character sprites -- if you are good enough in carrying out a sustained assault, the spell can be cut short and you can also get the special bonuses. With Lily especially, if you are firing at her up close and personal, you will find that she explodes more quickly (thus reducing the number of dots you have to deal with). In addition, the game helps you shoot down the bosses by giving a guide at the bottom of the field showing where the "Boss" is. If you can't see where they are due to the special effects, follow the guide.
Note that bosses gain more health the more times they are summoned (bottom right number indicates Boss level). However, as the match drags on everything has a higher point value and you get a free Boss summon at 100k, 300k and 500k Bpoints. Therefore you are unlikely to be able to get enough time to kill the boss before your own boss cancels her out (unless you deliberately stop firing sometimes to reset your score). In particular, casting a Lv 2,3 spell to defend yourself is almost guaranteed to destroy a lot of bullets late-game, massively boosting your score. Thus don't try too hard in late-game to bring down the boss unless you are above 500k Bpoints (Lily is another matter of course).
If you see a "G" special bonus drifting down at you, and you have a level 2, 3 or 4 spell, immediately fire it off so it can clear the area for you to get the bonus, plus give your opponent a giant headache at the same time. Ideally, you can get one or two level 2 attacks off AND fire the bomb for maximum pain.
If you can micro-control your character's movement, you will find that avoiding collisions will be much easier. Remember that even if objects intrude on your character's sprite, if they don't touch the critical area, you're safe. The game will award you bonus points if you steer your character extremely close to hazards without colliding. (By extremely close, I mean that usually the hazard would be within your character sprite.)
Cast spells by holding the "Fire" button down whenever possible. This has a disadvantage because whilst holding the "fire" button down, you are defenseless and can only dodge things. However, it allows more control over your spell casting and in addition your spells will recharge more quickly using this method.
USE your spells, don't keep them there "just in case". The more you use them, the quicker they will recharge, and the harder a time given to the enemy. If you find your character trapped in a corner or having a lot of obstacles charging right at your position, cast a level 2 spell to give you some room to move away from there. It will save you a few lives. Remember, spells destroy everything at a certain radius.
At very high Bpoints and bullet density, when timed right it is possible to gain an entire spell level from a well-timed level 2 spell that destroys a wide spread of spirits that would otherwise be impossible to entirely shoot down before they go off screen. Plan ahead by seeing when a large wave of bullets is coming towards you - each bullet and spirit that spawns will come from a blue (if 1P; red if 2P) cloud transferred when your opponent destroys the right objects.
The level 2 attack is your primary mode of defense. It destroys bullets, but mainly it gives you the vital second of invincibility to get away from patterns. Usually you want to reposition yourself to the center of the screen to get more options. In the later levels you will have to anticipate a little, especially with the slower charging characters. In fact, you cannot really afford to bomb, since the loss of meter will get you killed in a few seconds anyway.
The above is general advice. There are 2 general philosophies in playing styles described below. Decide which is more suited for you for each situation:
- Stop firing at times to flush the screen of bullets. If you destroy nothing, the opponent gets nothing to reflect back on you. This is less effective in Extra Mode -- if you stop firing for too long, the opponent's invincibility countdown will freeze until you begin firing again.
- Reset the Score Counter back down to 0 from time to time - it's ok to go up to 500k Bpoints but beyond that, reset so you get more free boss attacks.
- Spellcards can now be timed better for offensive usage, as you'll have more space to think and glance at your opponent's screen. Try to time with specific moments of your boss attacks.
- Get the Score Counter up to 999,990 and keep it there.
- Strive to destroy everything in sight.
- Use mostly just Fairy-class spellcards and spam them.
- More destructible bullets is a Good Thing - reflect as much as possible and expect to get most of them all reflected back again. This is why having an enemy boss raining down danmaku on you is also a Good Thing.
- Ideally, your spellbar fills just as fast as you drain it spamming Fairy-class spellcards. To achieve this, you need to stay at 999,990 Bpoints and there need to be a lot of bullets on the screen to continuously destroy. A well-shaped field greatly aids this as activated spirits help set off combos.
- You need to be confident in dodging very dense, but short-lived danmaku barrages. Match ends when one character can't take the pressure any more and collapses. The Hard AI usually can't go beyond 4 minutes (even with fast characters like Mystia).