Easy money
Simply find an empty can and kick it into the nearest trash can.
Get the Flame Barrier and an S Class Licensee then go to the Planet Elysium. Go into the defense area and proceed until you find a Reverbot that is flying above you. Do not kill it -- it will make three flaming Reverbots. Kill them and the flying Reverbot will make more. Repeat to get as much Zenny as needed.
When you kill a Reaverbot or anything else, go directly in the middle of the explosion while it is blowing up. You will not get hurt, and you will automatically get all the Zenny without it spreading all over.
Go to the ruins where the fourth key was held. Have the Vacuum Arm on and get to the fifth floor. Take out the missile bot in the center, then just run around destroy all the bots that appear. Use the Vacuum Buster to get the money so you do not get damaged. You can get over 100,000 Zenny in 10 to 30 minutes. This will help get more energy packs and upgrades faster.
Go to the Manda Island ruins after you get the class S license at the gallery or digout. Then, equip the Vacuum Arm and go back to the ruins, as long as you have already destroyed the first breakable wall with the Drill Arm. There will be a large bird statue (only if there is a chest at the beginning of the ruins). Kill it to get 6,500 Zenny with no guild license, 8,000 Zenny with the first level license, or 10,000 Zenny if you have a class S license. After you destroy the statue and get the Zenny, go through the door, then turn around and go back out through the door. The bird statue will appear again. Defeat it from the door, and once it starts exploding get very close to the door. Immediately after you get the Zenny with the Vacuum Arm, go back trough the door. Repeat this to get as much money as needed.
Go to Calbania and go out the door of Shu's place to see two red Reaverbots. Destroy them both to get 5000 Zenny. Go out and come back in and they will be there again.
The Reaverbot Eye that you buy from the man in Saul Kada can be sold to the owner of the junk shop in Yosyonke. Go through the back door. He will offer you 100,000 Zenny, but hold out for 300,000 Zenny. Do not ask for 500,000 Zenny or he will turn you down and when you ask him again, he will only offer you 10,000 Zenny.
After opening the ruins on Nino Island, go to floor B2. There will be some plate-shaped Reaverbots. Destroy and collect Zenny. Escape and repeat. Note: The Drill Arm would be useful.
There are two trash cans in Yosyonke, each with an empty soda can nearby. The trash can next to the general store gives you 200 Zenny when you kick the soda can into it (with "Square" or "Triangle"). The trash can behind the doctors office gives you 1,000 Zenny when you kick the soda can into it.
Go into Professor Barrel's room on the Flutter. The bed and one of the desks or dressers will have Zenny in them.
Getting concealed Zenny
Zenny may get stuck in the wall or on a mountain from time to time. To get the Zenny (Refractor Crystals) off the wall or side surface, simply stand next to it and jump. The Zenny will fall off the wall and you will land on top of it.
Very Hard mode
Acquire the Class S License and successfully complete the game.
Getting the Drill Arm
Get the Heavy Gear from the box to the right of the Sulfur-Bottom when you head to Bluecher. It is directly in front of the door to the right. You also need the Blunted Drill from the pottery barrels to the right of the building next to the ruin with the first key.
Getting the Cleated Shoes
Complete the Train level then go back through the train's entrance. You should run to an area with one box and will get the Spike Chip.
Cheaper Final Buster upgrades
Megaman can buy his Final Buster upgrades cheaper in Pokte Island if you do not allow the buildings to be destroyed or if you paid to have them be rebuilt.
Saving Data
At the start of the game, when you have to save Data in the fire, allow the fire to hit you until your life gauge turns red. Roll will turn on the sprinklers and you will not have to do any work.
Defeating Jellyfish
In the ruin in which you acquire the second key, take Drill Arm with you. If you are having trouble with the Jellyfish, get close to them. A full Drill Attack should kill one. Do this on all three of them. If done correctly without any setbacks, you should defeat them. You can also use the Drill Arm on . You should be able to defeat him easily if you use the Drill Arm correctly.
Defeating Shielders
If you shoot a Shielder with any high impact weapon, its shield will be blown away allowing it to be hit more easily.
Pig
After destroying Glyde's base, Shu will give you a pig. Sell it for 5000 Zenny. Do not give it to the girl on Nino Island, as she will eat it, which is what Shu told you not to do.
Picnic Lunch
Talk to Roll on the Flutter and pay the 4,000 Zenny to fix the kitchen and other areas Data burned in the fire at the beginning as soon as possible. Not only can you get the Broken Motor after it is fixed, but you also can talk to Roll and she will say "There's something I want..." She will ask for a new refrigerator. Buy it for her, then exit the Flutter and re-enter. Go to the second floor and to the kitchen area. Check the refrigerator and you will get a Picnic Lunch, which refreshes all of your life gauge. After you use it, you can return and get another. This way you can always have a secondary Canteen available. Use the Picnic Lunch first, so you do not have to use the expensive Canteen. Remember to use it only after down to nothing.
Cut down trees
After the train event in Yokeshstone, go to where the explosion is located. Look for trees. Equip the Drill Arm and hit the tree. It will either blow up or fall down.
Avoid burning or freezing to death
You can never burn or freeze to death if you are in the red with shield and on fire. Wait for the fire (or ice) to go out, then use your Canteen. Note: If you go out of fire and get hit by the "tongue" of fire or ice via a Shielder (or anything else that may set you ablaze, such as lava or ice pits) again, you will be terminated.
Special Refractor values
These are found after defeating a previous Boss or Bosses in certain ruins in the room after the defeated Boss.
Refractor B: 30,000 Zenny
Refractor A: 50,000 Zenny
Refractor S: 100,000 Zenny
Elysium Residential Area: Path through the light
On the beginning Island, you will see some portals open and some closed. Look at your mini-display-map at the top-left side of the screen and go to the portal until you on the map (the blue arrow) is pointing as close to directly up as possible. Enter that portal. Point the blue arrow on the map again and go up. There should be a flaming Reaverbot or two walking around. Defeat the bot(s) and point the arrow on the map right. More Reaverbots will be on this island. Take another right. Now go downward. There should be three Reaverbots marching around. Now, turn left and that should be the end of your trek. Go inside the building to save.
Nino Island: Killing enemies
On Nino Island, where you get the second key, you can kill the three jellyfish-like Reaverbots and the gigantic red fish-like Reaverbots very easily. After you flood the floor, walk towards the small passage where you must place a metal block on a button to pass. Very near to it, you can find another door leading to another elevator. Go up using the elevator, activate the computer systems to drain the water from the floor below, and return. Now, the red fish-like reaverbots harmlessly flop about, allowing you to destroy them to receive lots of Zenny. Along with this, the three jellyfish cannot move at all. Just shoot yellow energy spheres around, which are very slow. Kill them for more Zenny, along with the key.
Zero poster
Enter Yosolonke's Item Shop and go near the back of the store to see a poster of Zero with his Black Armor.