To get all the achievements you'll need to complete game twice, since Leisure Suit and Wedding Suit are mutually exclusive achievements. However, you can use this guide if you don't want to play whole game twice. But before that, you need to complete the game at least once and save at the end of the game (for example, in a retro simulation). Also the Die hard achievement is very easy to miss, so check the guide from time to time

Escape from Cancum Island
Leave the island aboard your raft


Faith!
Encounter Faith


Cockburn's Keystone
Get Cockburn's keystone


Marquis' Keystone
Get Marquis' keystone


Lady Gobbledick's Keystone
Get Lady Gobbledick's keystone


Muffington's Keystone
Get Muffington's keystone


The Cavern of Cosmic Cognition
Find the entrance to the Cavern of Cosmic Cognition


Total Recall
Speak to Faith in the Cavern of Cosmic Cognition


Back to NLW
Complete the helicopter mini-game. You can skip it. You still get the achievement


PiBot Connection
Upgrade a corrupted PiBot


Back to Reality
Escape the retro simulation


Wedding
Finish the game

Leisure Suit and Wedding Suit
Achievements are mutually exclusive. After you receive a distress signal from Faith and Larry decides to leave the island, you will be able to change between suits (just click on the suit in the cage again). You need to complete the game wearing leasure suit or wedding suit. You can't do it in one playthrough. Therefore, in the introduction there is a link to a guide that will help you get both achievements. Or just complete game twice

Wilma
On the island at the very beginning of the game, find lipstick, seaweed and a volleyball. Combine these three items. You must do this before leaving the island.

Die hard
You need to die in every possible way at least once. There are 6 of them in total. You don't need to save before dying because you'll be put back into the game just before you did whatever killed you. Deaths in the order in which they can be obtained:
1) On the island at the very beginning of the game, after you have made all the preparations for the wedding and received a distress call from Faith, talk to El Rey and choose the following dialogue options:
Now that I think about it...maybe the wedding isn't such a great idea.
I want to lay more women!
Not just laying. Standing works, too
2) Hotel - Observation Deck. After you get all four quarters, use the telescope and look directly at the sun
3) Pick up any orchid that is not a single blue flower with pointed leaves
4) Compass app. Click anywhere in the sea to see shark death
5) Compass app. Go to coordinates -20 / 3. Before that, you need to talk to Shauni to find out these coordinates. Make sure it's a rock death and not another shark death. Must be done after putting the fan on the raft but before putting the inflatable gator and the blow-up doll on the raft.
6) While on the submarine, interact with any object and when the alarm goes off, just wait for Yanmei to find you. This must be done before getting the stone from the safe.

Bing!
There is a bell at the reception desk in the hotel lobby. Use it until you get the achievement


Call me!
While playing through the game, you will need to dial a certain code on the phone in Swingle's hotel room to unlock the safe. However, you can call other numbers. To get the achievement, you need to call all of them. Just choose the white numbers. If all the numbers are grey, but you haven't got the achievement yet, back out of the phone and use it again to get new numbers

Get out of here and Worth the wait
Achievements are mutually exclusive. But they can be obtained if you manualy save the game. Or during the second playthrough. On the submarine, once you get the stone from the safe, Yanmei will appear and tell you to wait before leaving the room. Save. Now just wait. Yanmei will return, a cutscene will play, and you will get the achievement. Then reload and leave the submarine.

Wendi loves Otis
As part of the story, you will need to hook up Wendi and Otis. After you do this, you will have the opportunity to spy on them. On the Village Entrance screen find the new "Behind the Huts" hotspot. Once you click on it, a cutscene will play and you will get this achievement.

Is that still funny?
After you return the joke book to Lewis at the hotel, he will start reading his new repertoire. You need to listen to his entire speech. Just wait until you get the achievement

Space Quest
In the ruins, after you disarm the traps, you can run an adventure for the janitor who cosplays Roger Wilko from Space Quest. Choose the following dialogue options:

Sanitation Captain Roger
A floating head
Clean it