Tricks

I'm gonna sort these into three sections: stuff that's supposed to happen but is just hidden or not explained (hereafter Secrets), stuff you could easily stumble upon anyway (hereafter Bugs), and deliberate game-breaking (hereafter Exploits). The first category, being intended behavior, doesn't negatively impact game balance; the second doesn't make a big difference. But the third set severely unbalances things. I'd recommend against using those on your first playthrough, but I'm not your dad.

There are, of course, spoilers in this section, so if you haven't beaten the game, proceed with caution.

Secrets

Sound Test

Hold A and B on controller 2, then press Reset, and the game will start in Sound Test mode, where you can listen to the game's music. It will give no visual feedback to tell you which track is selected, but you can control playback with controller 1: B starts playing, A stops, and change track.

Bonus Energy Packs

If you defeat at least 200 enemies since your last visit to a save terminal, you'll hear the sound of a chest opening. When you next visit a save terminal, you'll receive an Energy Pack.

Running for Fitness

You can actually gain stats by running! Run away from battle enough times, and you'll hear the rank up sound—check your stats, and you'll find that your party members' PWR and SPD have each increased by 1. The first time, the required number is 8; each subsequent time, the number increases by an additional 8 (so 16, then 24, then 32...).

BTank Overcharge

During the Ozone City spacewalk sequence, if you ignore the hatch and float north or south for about 8 minutes, you'll hear the sound of a chest opening. Now turn around and go back for another 8 minutes to get back to the hatch and go in. Gene's BTank will be charged to 65535 BP. No, his maximum hasn't gone that high, unfortunately. And the Ozone City tunnels are full of enemies that will drain BP by half, so you won't get to keep that overcharge. This really isn't all that useful, but it's kinda neat, anyway.

Bugs

Skip the Spacewalk

When you've gotten the O2 Tank from Cosmo City, instead of heading to the Hatch 143 maintenance tunnels to spacewalk to Ozone City, take a shuttle to Vesta-2 and retrieve the HydroWing. This will let you fly directly to Ozone City, skipping that entire sequence. But don't think you can avoid the boss fight at the end of it—Ledesma has the NavBot3. But you'll have an advantage coming at him directly from the Ozone City save terminal.

(I did this one by accident my first playthrough. I unwittingly did the Ozone City tunnels in reverse, and couldn't figure out what the point of the hatch at the end was, since all I could do was go right back inside.)

Taking Advantage of Gratitude

As you make your way through the Weapons Stockpile, the members of the Potatia Unit will reward you with items when you find them. However, if you leave before finding their captain, their flags will all reset, and you can collect items from them again.

Exploits

Buy Hidden Items

Not, like, secret items—don't get your hopes up. But shops in every city have a hidden item for sale, and a different item in each city. As I implied in the intro, this is unintended behavior, this is not a deliberate secret feature; it's a way to get the item shops to try and sell you junk data sitting in the wrong memory address.

Here's how you do it: press Up like you're moving the cursor to ⏵Next, and press A simultaneously. You'll know it worked if it tries to sell you an item that wasn't listed for a price that's unrelated.

Shops Item Price Note
Isis City RoboFreeze 17790 Very early to acquire this weapon
Fiber City HeatSaber 6173
Iron City SolidGun 6169
Ceram City SolidGun 7725
Ozone City DiveBomb 5414
Satellite Base (int) SolidGun 24
Satellite Base (ext) HeatSaber 24 ...if you go directly to the shop from the elevator
Satellite Base (ext) SolidGun 21 ...if you visit the factory first
Potatia Town SolidGun 8469
Orangeria Camp IceRifle 6261
CornBase SolidGun 12335
CenterCity CorrodeSword 6423

The RKO guide, where I get this info from, indicates that the SolidGun at the Satellite Base (ext) shop seems to only occur on actual hardware, but as emulation has grown much more accurate since it was written, it's possible that's no longer the case. It might be more accurate to say instead, if you are emulating, the emulator you use may affect whether you get anything but the HeatSaber there.

...Buy for the Price of a BTank Trade-In

This trick has a corollary! When it asks you to confirm the purchase of the erroneous item, you can select No, go to the BTank sales panel, select any model, and select any character. It will tell you the normal trade-in value, and when you hit confirm, charge/rebate you that much; however, instead of swapping anybody's BTank, it will give you the glitched item! In practice, this is how you'd get that RoboFreeze early: for the trade-in toward a BTank500.

Absurd Experience

First, have at least one HavocBomb or the Daze tech to confuse enemies. Next, get in a fight with an enemy that uses Rapid strike, plus at least one more enemy. (The enemy can be the same, but it will be more effective if it's different.) Now confuse the rapid-striking enemy.

The enemy needs to use rapid strike, and it needs to kill its target on the first hit. Dying before the whole attack has resolved causes it to enter a glitched state. If the second hit lands and a strange message displays in the battle log (e.g., an absent enemy being defeated), then you've succeeded! Congratulations on too much experience.

Hack Any Weapon

Okay, yes, you're actually hacking the game for this one. It's not exactly a trick, but Cubear went to a lot of trouble to figure this out for me, so I wanted to record it somewhere. You'll need an emulator with debug tools; we're using Mesen in these example screenshots.

First, load up the game, open the debugger, and set a breakpoint at PRG $5B5A5.

Next, go pick up two weapons. They can be anything, even the cheapest BattleKnife. Take them to the Weapons Factory in Satellite Base, and select them for combination. This will hit the breakpoint, and emulation will pause. Now go change the value in register A to any value on the item table, which you can find at Data Crystal.

Now, instead of whatever the combination would have produced, it'll make the item you entered. It can even make robot weapons and other items!

It does not, however, give you any sort of discount (save for the cost of intermediate crafting steps for high-rank weapons). That Abs0Cannon is still going to cost 65,000kr.

(The reason I asked someone to figure this one out for me? So I could get all the images over on the Weapons page. It worked a charm for that, especially for crafting all the R1 weapons you can't easily make normally.)