Easy Levels, Sub-Tank Fill, Energen Crystals - After beating the first stage, it can be
revisited using the Trance machine by choosing the first option to transport and then the second option listed to transport to where the first stage took place. There are plenty of enemies here that can give you energy and such, including spiders that constantly
regenerate. Find one of these webs and stand in front of it, destroying the spiders as they come out. Several minutes of this will give you upgrades to any weapon quickly and easily, and the spiders will often drop life energy for filling Sub-Tanks and Energen Crystals for upgrading your cyber-elves. It is important that you DO NOT defeat Maha Ganeshariff if you still want to use this trick, because after he has been defeated the area cannot be visited again in this respect.
New Game Plus - Similar to games such as Chrono Trigger, after beating the game a new one can be started with your upgrades in tact. Simply wait for the credits to end and save your game when you have the option, and then select that game in the continue screen of the main menu. You'll start a new game with any effects from the cyber-elves still in use. Your weapons, however, will not be in their upgraded form.
Hard Mode - To play in Hard Mode, hold L while starting a new game after having beaten the game. You won't be able to charge any weapon but the Shield Boomerang in this mode, so elementals are quite impaired and your weapons stay at their basic model.
Ultimate Mode - Starting a game with Jackson in your inventory (see below), you must use all of the elves and then beat the game. After this is done you will unlock Ultimate Mode. Access the mode by holding R and starting a new game. In Ultimate Mode all of the permanent elf effects are already active, and all weapons are at their max levels from the start. Also in this mode, rank isn't affected by use of the permanent elves, since they are used automatically. And in Ultimate Mode, Zero can perform key combos to do charged attacks without having charged, similar to his attacks in X4-X6.
The Rare Elf Jackson - To collect Jackson, get all of the elves in the game and get them to their max status in normal difficulty. This also unlocks Ultimate Mode (see above).
Zero's Combo Attacks - In Ultimate Mode (see above), key combos can create charged attacks. The following is a list of the button combinations
d = down; df = down + forward; f = forward
Buster Shot
Charge level 1: d, df, f + attack
Charge level 2: d, df, f (2x) + attack
Z-Saber
f, df, d + attack
Triple Rod
f, d, df + attack
Shield Boomerang
d, df, f + attack