The Researcher.

WARNING this achievement is missable.

At the start of the game once you gain control over Christian the snail, slither on over to the console in front of the large display screen and press any key on your keyboard to bring up the command prompt, type "use" and then hit enter.

A "Main Menu" will then appear on the screen, press number 4 on your keyboard to enter the Encyclopaedia and proceed to read about the three species on record by pressing 1 to read about the Zhawks, 2 to read about the Octoids and finally 3 to read about the Kytans.

Once you have read up on all three of the species, repeatedly press the Spacebar on your keyboard until you back out and eventually shut down the display screen and this achievement will pop.

The Investigator.

Uncover the first big mystery.
After exiting from the console, head over to the stasis pod in the bottom left (the one below the pod you emerged from), press any key to bring up the command prompt and type "open pod", then hit enter to release Zoomer from stasis.

Next head on over to the pod in the top right of the screen, again bring up the command prompt and enter "open pod" to release Shelley.

With both your living companions now released from their slumber move over to Shelly, press any key on your keyboard to bring up the command prompt and type "ask Shelley about Zoomer" and after she finishes responding head over to Zoomer, bring up the command prompt and type "ask Zoomer about Shelley".

Conversations over, head over to the machine up against the right wall, bring up the command prompt and type "open machine", Shelley will then come over and help you open the Lettuce-O-Matic, to only discover that it is broken.

Bring up the command prompt and type "get can" to obtain the watering can from the machine, then head over to the closet against the left wall, bring up the command prompt and type "open closet".

Zoomer will then come on over and help you to open the closet, once open, bring up the command prompt and enter "get mop", mop in hand bring up the command prompt a second time and enter "get wrench".

Lastly, head on over to the broken stasis pod in the bottom right, bellow Shelley's pod, bring up the command prompt and enter "use wrench". Shelley will then come over and break the pod open and after the set piece conversation, this achievement will pop.

EVA Explorer.

WARNING this achievement is missable.

After "The Investigator" achievement pops, move over to the yellow puddle that came from the captains broken stasis pod, open the command prompt and type "get tentacle" to obtain the remains of the captains tentacle.

Tentacle in hand, head over to the red circle on the floor, just below Zoomer's pod, in the bottom left of the screen, bring up the command prompt and type "open hatch", and exit through the hole into the airlock.

Move over to the red button on the left wall and bring up the command prompt and enter "scan tentacle", then bring up the command prompt again and enter "push button" to open the airlock.

Once the airlock is open, exit the ship through the hole in the floor, beware that movement outside the ship is done via thrusters and as space is a void, inertia is something you will need to compensate for.

Once you are outside the ship, fly towards the left and when you enter the next area of space, float around for a few seconds and this achievement will pop.

Existential.

Die in all possible ways.
WARNING this achievement is missable.

Once the EVA Explorer achievement pops, fly upwards and exit at the top of the screen, where you will promptly float off into space and die (this will be your first of two ways to die, required for the Existential achievement).

When prompted, select "Try again" to respawn at a checkpoint back in the airlock aboard the ship. Note that you just lost a point from dying, this is because a point was awarded for exploring the area of space to the left of the ship and when you died it reverted to a checkpoint (game save) before you explored the area.

As we need a score of 46/46 to earn one of the game's achievements, exit the airlock and head back to the area of space to the left one again to reclaim the lost point.

Once back up to 23/46 points, head back to the right to the area of space directly under the ship and move up to the right hand landing gear protruding from the underside of the ship. Bring up the command prompt and enter "use wrench" to repair the landing gear and then return to the inside of the ship.

Once inside the airlock, move over to the red button, bring up the command prompt and enter "push button" to close the airlock door and then head up, back into the main room.

Finally, head over to the butter puddle next to the captains broken stasis pod, bring up the command panel and enter "use mop" do die in the second possible way and earn this achievement.

Touchdown.

Land on the lettuce planet.
Once again after dying select "Try again" to load the checkpoint (at the airlock floor hatch in the main room before using the mop), this time around, there were no points lost.

Now head over to the yellow panel on the floor to the left of the cabinet Zoomer opened up earlier, bring up the command panel and type "move panel", bring up the command panel once more and enter "go down" to enter the service ducts under the floor.

In the tunnel, move over to the far right and then bring up the command panel and enter "drop can" to place the watering can below the floor grate in the room above, then return upstairs by simply moving all the way along to the far left.

Back upstairs, once again head over to the butter puddle, bring up the command panel and enter "use mop", this time instead of blowing the ship up, the butter runs through the floor grate and is collected in the watering can below.

Head on back over to the floor panel by the cabinet, bring up the command prompt and type "go down" to return to the service tunnel. In the tunnel move over to the watering can, bring up the command prompt and enter "get can" to collect the watering can full of butter.

Return to the room above by walking all the way to the far left and then move over to the ship's engine, located at the bottom of the screen in the centre. Bring up the command panel, enter "use butter" to fill the engine.

For your final act, move over to the console at the bottom of the display screen where we earlier viewed the Encyclopedia and one last time bring up the command panel and enter "use console".

At the main menu on the display screen, press 2 to enter Navigation, then 2 again to leave orbit and land on the planet and lastly option 1 to confirm. Then watch the final cut scene, the game will end and this achievement is yours.

High Achiever.

Obtain the maximum score possible.
WARNING this achievement is missable.

This achievement pops at the same time as "Touchdown" does if you complete the game with a score of 46/46, which you will if you follow the information in this guide or my video walkthrough.