How to get to the blue armor in level 25, Perfect Hatred:

First, you need to get to the lava pool in the large room
just to the west of the level's starting point:
When you start the game, Run (remember your Run button) up
the left-hand ramp, to land on the west-side platform ahead
of you to the north.
To your right is a pillar with a switch on it.  Activate it
to open a door high up in the west wall, behind you.
Run west off the platform you're on to jump through that
new doorway in the wall.

Just inside and below that doorway is a switch.  Activate
it.  Just to the left of the switch (just north of it) is a
small triangular spot in the corrosive pool that covers the
floor of this room.  If you step into this spot, a narrow
section in the middle of the north wall of this room will
rise up, revealing a stairway that leads up and north.

Go up the stairs, and you'll see a red teleporter pad on
the floor, several paces ahead of you to the north.

Walk up to the teleporter but don't step on it.  Instead,
search the wall to the left, just before the teleporter.
A secret wall panel will rise up, revealing a very short
passage that runs north.  Walk into this passage, and walk
to its far end.
Search the wall to your right, and you'll find another
secret panel that opens up to a spot that's just behind the
teleporter you saw a moment ago.
Turn and step south onto the teleporter.  Stepping on the
teleport pad from this side will send you to that room in
the northwest corner of the map, where the blue mega-armor
can be accessed.