Full Ammo On Level 1 of Pac-Guy
On the first level of Pac-Guy or Pac-Guy: Resurrection, look to the left of where you start. There are three blocks, then a space you can actually move onto, then a fourth block. This fourth block is a fake. Walk through it to end up outside of the level. there will be a flashing square in this outer area. Grab it and your ammo will be full.
Full Ammo On Level 2 of Pac-Guy
When playing the second level of Pac-Guy or Resurrection, look for a block that is lighter then the others. The block two down from this discolored one is hollow. Go through it to get to the outer part of the level, where you'll see a flashing square. Picking it up will give you full ammo.
Full Ammo On Level 3 of Pac-Guy
Look for the flashing square. Look at the block farthest to the right from this square. Walk through this block to end up on the outside of the maze. Then grab the flashing square mentioned earlier to max out your ammo.
Full Ammo On Level 5 of Pac-Guy
There is a block with a thin black outline around it. the blocks two blocks to the left of this one is hollow. Go through it to get to the flashing square that will max out your ammo.
Full Ammo On Level 6 of Pac-Guy
Go through the hollow block (outlined in black) to get to the flashing ''full ammo'' square.
Full Ammo On Level 8 of Pac-Guy
The block four places right of the one below you (when you first enter the level) is hollow. Pass through it to get to the full ammo power-up.
Full Ammo On Level 9 of Pac-Guy
This level is pretty much a straight line with a couple parts branching out. Once you get to the very end (past the guns) move to the right through the hollow block. The full ammo power-up is in this area.
Reach The Power-up On Level 1 of Pac-Guy 2
The block to places up and five left from where you start is hollow. Passing through it will let you get to the shield in the level.
Reach The Power-up On Level 2 of Pac-Guy 2
At the start of this level, move forward, then go all the way to the right. You'll pass through the block there, and be able to get to the invisibility power-up.
Reach The Power-up On Level 4 of Pac-Guy 2
The block two spaces up and six to the left from your starting point is hollow. You can pass through it to get to the full ammo power-up.
-from Chao of Time