This guide will walk you through how to get all of the achievements, and I have put the achievements in roughly the order in which they can be earned. While it is technically possible to earn every achievement in a single playthrough, it may be necessary or helpful to start a second playthrough to finish the last few.

Since this is the first full achievement guide for this game, please feel free to comment more details about how any achievements work and I will update the guide.

The following achievements are time-sensitive within the game, so it is possible them if you don't do them right the first time.

Throughout the game, it is helpful to:
-Defeat all bugs and pick up their antennae
-Defeat all spiders
-Defeat all flies
-Smash things in general

Almost impossible to miss. At the start, talk to the man south of you and give him the megabomb.

Defeat Arik, the boss of the first area. This is an achievement that you can potentially get in the first playthrough, but it is easier to get on a fresh save file after having played through more of the game. You cannot re-enter this cave after completing the first quest. To defeat Arik, go through the rest of the cave without taking damage, and then carefully damage him when he is in his hit animation.

Also nearly impossible to miss. Grab the book at the end of the first door.

Hit 20 enemies with one hammer swing. The easiest way to get this one is to find a door with several fly spawners in close proximity. Simply walk around near the spawners, allow 20+ flies to spawn, walk around them so they become clustered together, and then turn around and hit the cluster. It might take multiple tries, but the spawners will keep producing flies indefinitely.

Have at least 400 (possibly 500?) coins in your inventory at one time. This one is really easy if you beat several doors in The River and wait before stocking up on bombs or armor.

Located in the Suburbs, in a door south of Ray's house, this boss is accessible early on. However, I would highly suggest coming back later once you have better armor and more health. To beat Pumpkinello, place pumpkin bombs and try to lead Pumpkinello to them, while constantly walking around. You will want to have 36 bombs just to be safe.

Defeat the great cactus. After becoming red (see this guide), talk to the guards in The River, give them the dye, and enter the door. To beat the great cactus, just walk around the edge as he is shooting thorns, then place a bomb by him when he throws out the bomb thorns.

After Ray blows himself up, grab his sunglasses off the ground and equip the sunglasses.

Upgrade diamond armor to max. There are more than 4 diamonds that can be gotten from doors, thankfully, but each upgrade requires you to talk to a different person, and one of the upgrades is time-sensitive. The first upgrade is with the guy in diamond armor south of Ray's house in the Suburbs, the second is with the merchant in Hedgehog Pasture, the third TIME SENSITIVE(because he gets killed)upgrade is with the mushroom guy in Mushroom Grove, and the fourth is with one of the men in the village in the Blue Forest.

When you first enter Mushroom Grove, agree to lead Mr. Bee to the island to the southeast. When he thanks you, say it was nothing, and decline the money. Then, talk to the bee at the gate in the hive, who will let you through, earning you this achievement.

Hard to miss. Pick up a bee glue in the hive.

Defeat 50 bees. The majority of bees in the game spawn in or around the hive, so it is worth defeating 50 of them (or at least 40-45) in the hive, dying or exiting without saving and coming back if necessary, since enemies do not respawn after being defeated.

Explode the main door. This boss fight is found in the City Walls after progressing through the rest of the story, and the fight can be completed before you are done with everything else, because the game doesn't save after the fight. To beat this boss, place the mushroom bombs that are dropped, and then use the Megabomb on the door.

Break the beetlejuice cauldron. After completing all of the trials to join the Beetle Cult, (three trials are in the cave, the fourth is in the south part of Hedgehog Pasture) give the cauldron 50 bug antennae to receive a Beetlejuice, and repeat this over and over until you run out of antennae. After a certain number of times, it will explode, earning you this achievement. If you haven't already beaten most of the doors, you might have to come back once you have more antennae.

View all the journal pages. See this guide for more info.

Collect all the gold keys. See this guide for more info.

Defeat all of the doors. If you are missing doors, be sure to check the map. I believe this includes unlocking all of the doors that require 3 gold keys to open, but there are several spare gold keys by the end of the game (3 or 4 from what I remember).

These achievements are not tied to the story and simply count how many times you have killed or done something.

Drink 200 pots of compote. If you haven't already gotten this one yet, you can simply drink every pot of compote in your inventory, exit the game without saving, and rinse and repeat until you are at 200.

Squash 200 chests. You should get this by the end of your first playthrough if you beat all the doors; if you don't, it should not take long in a second playthrough.

Die 25 times. If you made it this far without dying 25 times, and have beaten all the doors, you can always kill yourself on the hedgehogs in Hedgehog Pasture.

Squash 2,000 objects. If you don't already have this one, there are lots of squashable objects lying around to get you to 2,000.

Defeat 50 spiders. You should get this one after defeating all the doors, but if not you'll probably have to start a new save file. There are also several spiders in the room after you join the Beetle Cult, which you could farm by exiting without saving, if they are still alive.

Kill 1,000 bugs. This one is possible to get in the first playthrough, but bugs are so common in the game that starting a second playthrough to get the last few does not take long.

Kill 1,000 flies. The easiest way is to find a door with several fly spawners near each other and just kill flies until you get it, if you don't already have it from beating all the doors. There are several doors accessible early in the game with fly spawners.

I sincerely hope this guide helped you in getting all of the achievements. If you found it helpful, please remember to like it and to possibly give it an award. If something in this guide is missing or incorrect, make a comment and I will update it.