1-1: City Center

Get the blue shard.
Rescue the captive.
Exit the level.

1-2: High Rise

Grab the keycard. And some ammo to the left also.
Scurry up all the ladders and lifts to the captive. An extra life is behind one of the doors.
Run right, pop the lock on the exit and...well, exit.

1-3: City Park

Go for the invincibility to play it safe. There's also a secret level up there.
Jump along the top to the captive. If you fall (red), it's okay, just get back up top.
Fall down the right side. Climb the tree if you miss the exit passage.

1-4: South Side

Take the first elevator to the first level. Green shard in the first door.
Leave the building, go to the next and climb to obtain the key card.
Drop down a couple levels and use the keycard to free the captive.
Go back up a few levels and use the green shard to drop a stone to the right.
Now, shove the stone to the right and cross the spiked pit. Do not fall in, it's death.

1-5: Sewer

This sucks. Not so good death shortcut after the blue shard. Extra life in the white door.
Go to the bottom left and through the door to save the captive.
Go directly right to GTFO. No other useful items.

1-6: Cave

Down a ladder and up a lift to the left, activate the switch. Secret level is easy to accidentally hit.
Continue downward past the unlocked bridge, through to the key card.
Go left, use the keycard, down, activate elevator, go right on the platform. Extra life. After the cyan shard, take a death.
After the death, go up and right to free the hostage.
Now, the long part. Just zig and zag to the exit.

1-7: Skull Man

Go right and start unloading your weapon into the boss. The left platform goes higher than the right. Also, there is a Robo-Buddy up top for extra firepower. When you kill this boss, a shard will drop. Use it to exit.

1-8: Elevator

Not much here. Pop the first switch and hop platforms like mad to the top. There is a switch near the surface that you will need to hit in order to continue.

1-9: No Man's Land

Straightforward. Don't die. Don't bother with the secret above the hostage.

1-10: Lab Entrance

Cyan shard is on the next floor up, near where it's used, convenient.
Spend the cyan shard and free the hostage.
Not much to do but exit. Extra life in the white door.

1-11: Computer Core

Orange->Pink is the intended path (cyan+red->blue shard). Red is the fast path - you have to time the jump at the very right side of the platform and commit fully, or die.
After the blue shard laser, get the key card.
With the key card, go to the cyan laser. If you skipped the first laser, you must also skip this one in the same fashion. If you took the safe route before, you should already have the cyan shard. Activate this checkpoint!
Drop down and rescue the hostage. Now, take a death.
Respawn above, and simply exit the level.

1-12: Mangle's Last Stand

Get to the elevator and stock up, then unload! Low on health? Use the extremely 'secret door'.

2-01: Outer Woods

A very straightforward level. Hit the switch and enter the fortress.

2-02: Main Corridor

Walk right and climb up the rightmost ladder to get the blue shard on the rightmost door. It is possible to hop across the top but it's really difficult and not really worth the time loss.
Continue right and up. Go through the first red door you see a couple times. The hostage will be there waiting.
Leave the hostage room and continue right to the exit.

2-03: Ant Caves

Start by jumping right for the ammo, then run at the left side of the elevator - you will fall through. Right, left, right and grab the key card.
Pretty much hold left and open the door for the red shard.
Return to the top of the ladder, right, insert red shard to activate the elevator. Ride it up, go left, rescue the hostage.
Make your way down, zig and zag until you get to the code room.
In order: CYAN, RED, PURPLE, GREEN, BLUE – 5 1 2 4 3.
Fall down through the opened passage and continue to the exit.

2-04: Ant Town

Practice This. Sometimes blocks need to be ridden down a little before the jump. Low jump the red section. This section cannot be redone - the whole level needs to be hard reset.
Not out of the woods yet. Donk your head on the log when going right, carefully zag up and left. Activate the platform and ride it up to activate the checkpoint. The lift does not stop and will buck you off into the spikes.
Go right, grab the invincibility up the ladder in the hut, back down, jump through the spike on the right (it's a shortcut), continue to get the green shard.
Go back up the lift, go left a bit, make a couple jumps, insert the green shard to the right.
Go left and push the block to the left until it falls. Rescue the hostage.
If you have lots of health: continue on the orange path. If you lack health: take a death shortcut instead.

2-05: The Queen

Go right and hook underneath to get the gun. At this point one bee will attack you, kill it.
Ride the lift up and park yourself where indicated. Face left and fire at the queen when she approaches. It should be possible to do her in within 2-3 cycles.
The queen drops the key. Grab it, open the door, get keycard, use keycard, exit.

2-06: Trash Dump

Go right. Avoid the spikes on the trash cans. Ride the lift up and continue. The invincibility can be grabbed only when the lift is at the bottom. Take it and climb up a couple levels, run past the guns to get the cyan shard.
Activate the checkpoint. Return left, go down a level, go right to exchange the cyan shard for a green shard.
Take a death and respawn up a level. Spend the shard, rescue the hostage.
Go back up, left, up, right - proceed to the exit.

2-07: Trash Boss

Duck to avoid flying trash. Use the platforms to get some powerups if needed. The boss drops a key which is for the door that contains the key card.

2-08: Electronics Lab

Go right. At the ladder, activate the checkpoint to the right. Then go left and grab the blue shard.
Go right, down, left through the TF ray, down, right again, through another TF ray, go up and rescue the hostage.
Go right. AVOID THE CHECKPOINT by jumping over it. Open the door to get the green shard.
Go down and take a death. Respawn at the above checkpoint, go right, use the shard and exit key to leave.

2-09: Genetics Lab

Go right, down one level, and left to get the blue shard.
Go back right and ride the platform up to the top level, then go right, down, left for the green shard.
Continue down three levels, go right, wait for the long platform, go up and right, down 1 level, cyan shard.
Go right, drop 2 levels, spend cyan shard, down 1 more, spend remaining shards, get nuke.
All the way to the top right, rescue the hostage.

2-10: Specimens Lab

There's nothing here but an easter egg. Exit the level.

2-11: Killer Pillers

Jump across all the lifts to get the key on the right.
Jump back left across the platforms and go up to get the key card. The plasma bolts to the left can help for the next part too.
Go right, up the ladder, left, rescue the hostage.
Go back right, drop down, and get outta here.

2-12: The Enforcer

It's all movement tech. The invulnerability can last you until the boss at the end, if you're fast enough.
Just empty everything into the boss. It drops a blue shard, which you will use to escape. Plant the nuke too.

3-01: Barricade

Continue right into the fortress, avoiding the mines, and go up and left to get the blue shard.
Continue to climb the level and go left, unlocking the laser along the way to exit. Health is required.

3-02: Fort Entrance

Right, up all the ladders you see, grab the cyan shard.
Go right, up the next ladder, follow the top of the level to the left and rescue the hostage.
Go back to the right, up the first ladder you see, continue right and exit.

3-03: Guard Tower

Go all the way right, get the key, go all the way left, open the door for the blue shard, go all the way right, unlock, and grab the green shard.
Return back through, insert the green shard, and zig zag climb to hit a switch to increase the right platform's range.
Ride up the platform, climb the ladders, go right. Knock the first block down (don't stand on it), then hop across the other three. Go right and drop to get the green shard.
Go up the ladder and hop up the platforms. Go left, fall and insert the green shard. Climb to get the hostage. There's a secret level on the top gun.
Hit the switch by the hostage for a bridge to the end of the level.

3-04: Cyborg Trouble

Go up some ladders and get the green shard.
Climb up two more ladders, spend the green shard, use the bottom path all the way right to get the blue shard.
Return left on the top path, down a level and right to disable the laser with the blue shard. Go right, down one level and right to get the cyan shard.
Rescue the hostage just above you.
RNG TIME! Dropping down can result in an instant unseen death. Do it anyway, you won't respawn far if this happens. Exit the level.

3-05: Goliath!

Pop the switch immediately and ride the lift up to get plasma bolts.
Hop back down and duck at the bottom step. Stand back far enough so you don't get clobbered. Just unload and pray.

3-06: Armory

Get 2 keycards from the doors. Activate the switch, ride the lift up two floors, go right and get the blue shard.
Go left, down to the bottom, up the ladder, use the blue shard, rescue hostage, exit.

3-07: Mutants Attack

Up ladders to the top, right for a while, grab the blue shard.
Go back left, below the platforms, then all the way to the right to exchange the blue shard for a cyan shard.
Go back left again, up past the platforms, ride it up, and go to the top level. Go right to rescue the hostage.
Go left again, drop down a level, then run all the way right to exit the level.

3-08: Robots Attack

Boring and full of monsters. Zig zag upwards to get the blue shard.
Go right, drop down a level, go left to rescue the hostage behind a blue shard laser.
Go right, climb up a level, and head for the exit.

3-09: Utility Maintenance

Firstly, get the radiation pill.
The blue shard is not far - go right, drop down a level, door on the left.
Left, drop down, right, drop down, right to rescue the hostage.
Climb up and out to the upper right.

3-10: Main Control

Grab the invincibility potion in the entrance. Climb up 4 levels and get the blue shard.
Go left to the ladder, up to the top, right to get the cyan shard.
Grab the invincibiltity potion. Go along the top of the level, left, pop both shard locks and rescue the hostage.
Go back right, down two levels to the checkpoint, pop the laser, and take the leap of faith to the exit.

3-11: Circle of Death

Be careful to avoid the flying robots. Go up the ladder carefully and all the way to the right to get the blue shard.
Climb the disappearing block puzzle. A secret level gem has 5 extra lives to the right. Climb up and go left for another block puzzle. Hit the checkpoint.
Go left. At the ledge, watch for an opening between the robots. Drop down and grab the cyan shard. Take a death for a shortcut.
Pop the cyan shard lock and rescue the hostage.
Prepare to die a whole lot returning to the bottom level and going right to the exit. The robot circle is nasty.

3-12: Master Cain

Get your butt to the right side and get those powerups and the checkpoint!