Controls
The game doesn't do the best job of explaining the controls, so I'll cover these briefly.
WASD or Arrow Keys - Moving your "cursor" yellow square around the grid.
E - Opens menu, used for using, examining and combining items.
F - Picks up or drops an item.
Alt - Rotates an item you are holding.
P - Resets the puzzle. Word of warning, this has no confirmation.
Esc - "Backing out" of an action - i.e. if you accidentally try to combine something and you want to stop trying to combine it? Escape.
Q - Can quickly switch between the two grids
Item Checklists
There are two achievements where you may want to track items for, which are "Can I eat that?", for using every health item, and "Did you catch the reference?", for examining every item. If you want to copy this list somewhere and tick off which you use/examine as you do so, you may save yourself some time.
Health Items First Aid Spray
Brown Egg
Green Egg
Sardine
Rotten Sardine
Green Herb
Herbs Vial (G+G)
Herbs Vial (G+G+G)
Herbs Vial (G+R)
Herbs Vial (G+Y)
Herbs Vial (G+R+Y)
Weapons Handgun
Shotgun
Rocket Launcher
DMP
Riotgun
NK-13
Killer6
Fixed Butterfly
Dlaser-935
Ammunition HG Ammo
SG Ammo
MP Ammo
MG Ammo
RF Ammo
Other Items Blue Gunpowder
Red Gunpowder
Green Gunpowder
Red Smoke Grenade
Green Smoke Grenade
Yellow Smoke Grenade
Red Herb
Yellow Herb
Herbs Vial (R + Y)
You may not encounter all of these items through natural gameplay, which is why I recommend using this as a checklist so that you can revisit after completing to examine/use the ones you missed. You will most likely miss Herbs Vial (G + G) and Herbs Vial (G + G + G) if following this guide to the letter.
Notes Before Starting
The images represent what needs to be in the "inventory" to complete it. This is all assuming that you reload your guns appropriately, and heal when appropriate too.
Later on, there are levels where you can fail a level by combining the wrong item, by using an item in the wrong order, by using the wrong item, or even by reloading guns in the wrong order. I will try to point this out whenever it happens. If I don't mention it, it is probably safe to assume that it is fine to stack ammo, heal, and reload as appropriate.
Level 1
After examining the gun, you should have the "Stranger, now that's a weapon!" achievement.
Level 2
Level 3
Level 4
Level 5
Level 6
Filling out the level this way should unlock the "You're not ready yet!" achievement. After you get this, reload the guns and you should then get the "Magic Pockets" achievement and be able to continue to the next level.
Level 7
Level 8
Level 9
Level 10
Level 11
Filling the level out this way first should unlock the "Not enough health, Stranger" achievement. After you get this, use the First Aid Spray and you should get the "First Aid" achievement and be able to continue to the next level.
Level 12
Level 13
Level 14
Level 15
Level 16
Combine the two Green Herbs into Herbs Vial (G+G), then use this to heal. This should get you the "Chamber's pupil" achievement. Remember to examine the item to save time later!
Level 17
Attempt to use the Red Herb from the menu. This should unlock the "Wait, that's illegal" achievement. After this, you can combine it with the Green Herb to make Herbs Vial (G + R), and use this to heal.
Level 18
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Level 19
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Level 20
Use one of the Green Herbs.
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Level 21
Eat the Rotten Sardine to unlock the "Intoxicating Power" achievement.
Use the regular Sardine to heal.
Level 22
Eat both Green Eggs.
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Level 23
Eat one Green Egg.
Use a Green Herb to heal.
Eat the other Green Egg.
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Level 24
Eat Rotten Sardine.
Use First Aid Spray to heal.
Eat Rotten Sardine.
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Level 25
Eat Rotten Egg.
Use Green Herb to heal.
Eat Rotten Egg.
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Level 26
Combine Red and Red Gunpowder.
Combine Blue and Blue Gunpowder.
Reload Guns
Level 27
Combine Red and Red Gunpowder.
Combine Blue and Blue Gunpowder.
Combine Green and Green Gunpowder.
Reload guns.
Level 28
Combine Blue and Green Gunpowder.
Combine Green and Green Gunpowder.
Reload guns.
Level 29
Combine Red and Green Gunpowder
Combine Red and Red Gunpowder
Combine Blue and Blue Gunpowder.
Reload guns.
Level 30
Combine Red and Green Gunpowder.
Combine Blue and Green Gunpowder.
Combine Red and Red Gunpowder.
Combine Blue and Blue Gunpowder.
Combine Green and Green Gunpowder.
Reload guns.
Level 31
Eat Sardine to heal.
Combine Red and Green Herbs.
Use Herbs Vial (G + R) to heal.
Combine Red and Red Gunpowder.
Combine Blue and Blue Gunpowder.
Combine Green and Green Gunpowder.
Reload guns.
Level 32
Eat Brown Egg.
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Combine Green and Green Gunpowder.
Combine Red and Green Gunpowder.
Combine Blue and Blue Gunpowder.
Reload Shotgun first.
Reload other guns.
Level 33
Use Green Herb to heal.
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Combine Red and Red Gunpowder.
Combine Red and Green Gunpowder.
Combine Blue and Blue Gunpowder.
Combine Blue and Blue Gunpowder.
Reload guns.
Level 34
Use Green Herb to heal.
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Combine Red and Green Gunpowder.
Combine Red and Red Gunpowder.
Combine Green and Green Gunpowder.
Reload Fixed Butterfly first.
Reload other guns.
Level 35
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Combine Red and Red Gunpowder.
Combine Red and Green Gunpowder.
Combine Green and Blue Gunpowder.
Reload Fixed Butterfly first.
Reload other guns.
Level 36
Eat Rotten Sardine.
Eat Sardine to heal.
Combine Green and Green Gunpowder.
Combine Red and Red Gunpowder.
Combine Red and Green Gunpowder.
Combine Green and Blue Gunpowder.
Reload Fixed Butterfly first.
Reload other guns.
Level 37
Eat Green Egg.
Use First Aid Spray.
Eat Green Egg.
Use First Aid Spray.
Combine Blue and Blue Gunpowder.
Combine Red and Green Gunpowder.
Combine Red and Red Gunpowder.
Reload guns.
Level 38
Eat Rotten Sardine.
Eat Sardine to heal.
Combine Red and Green Herbs.
Combine Red and Red Gunpowder.
Combine Red and Green Gunpowder.
Combine Green and Blue Gunpowder.
Combine Green and Green Gunpowder.
Combine Blue and Blue Gunpowder.
Reload guns.
Level 39
Eat Green Egg.
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Eat Green Egg.
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Combine Red and Yellow Herbs.
Combine Blue and Blue Gunpowder.
Combine Blue and Blue Gunpowder.
Combine Green and Green Gunpowder.
Combine Red and Green Gunpowder.
Reload Shotgun.
Reload Fixed Butterfly.
Reload other guns.
Level 40
Eat Green Egg.
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Eat Green Egg.
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Use Herbs Vial (G + R + Y) to heal.
Combine Red and Yellow Herbs.
Combine Herbs Vial (R + Y) with Green Herb.
Finishing upYou should now have unlocked all achievements for level completion and most other miscellaneous achievements. If you are still missing the two achievements for examining all items and using all health items, you can reopen a level and make the items you need to eat/examine. Level 40 is a good one for this as it has a lot of herbs. Hopefully, you followed my advice on using the checklist and this shouldn't be an issue.
Source: https://steamcommunity.com/sharedfiles/filedetails/?id=2801001496