Most of the achievements in this game are storyline related and pretty much straightforward with exception of Uncharted but still you can knock everything out within an hour.

Currently the Uncharted achievement is broken in main branch but it is achievable in beta branch (Credits to lylat). I recommend starting the game in beta if you want to get through all the achievements in one go.

To switch to beta branch, go to Library. Right-click on the game and select Properties. Go to Betas tab and from drop down asking Select the beta you would like to opt into, select testing branch and click Close. Once the game download has finished you can proceed as normal and start a new game.

The latest patch has been reported to have fixed the issue with Uncharted achievement not unlocking. So no need to switch to beta build anymore (unless you really want to).

• W,A,S,D - Movement
  
• Lift-Click/Space-bar - Attack
  
• Q - Special attack
  
• E - Interact

Enemies in this game can be a pain as they land speedy and powerful attacks but they cannot regenerate their health. The controls in this game aren't very refined and many times hard to be precise. However there are many bugs too which can be helpful in glitching out enemies. You will always find enemies near shrines. You can pretty much run past them and place offering on shrine and skip them out altogether. However, if you prefer to fight them the best strategy is running around them and using special attacks to land blows at safer distance. Also remember to use favors. There are 4 favors, viz. Smash Up (which increases Special attack power), Attack Up (increases attack power), Health Up (increases health) and Speed Up (increases your movement speed). Whenever your health is low, just switch to Speed Up and run and heal with Taro plants. When you come back you will still see enemies with same health bar and you can finish the job incrementally. Another thing to keep in mind, is that when select Favor from Gods, you can point the circle in middle to have a combo of two power ups (I found combo of Speed Up and Smash Up quite useful, and even Health Up and Attack Up is very powerful combo). If you die however you will restart from last checkpoint.

Once you start the game you will be pitted against a Dino (henceforth called Barney). As soon as you start, press Q to break his shield. Keep running around him and landing special attacks. Once Barney keels over you will unlock this achievement

This will automatically unlock after defeating Barney


After Barney is dead, you will be transported to main island where an old guy (henceforth known as Roshi) is explaining to you about Gods and Taro. You will be instructed to eat a Taro plant and also be taught importance of sowing seeds after you eat it. This will pretty much unlock automatically at this point.

Opposite from Roshi and Taro farm will be a Temple like structure as seen below. Just Press E to read and you will unlock this achievement.





To get this achievement you have to offer a coconut at Shrine of Ku. From starting point behind Roshi you will notice that there is a winding uphill path on the left.







Continue up and you will notice some enemies. There is also a palm tree on the right. Switch to Smash Up and press Q near base of tree until a coconut falls. Dispose the enemies as you please, pick up coconut and head to Shrine. Alternately you can just pick up the coconut, switch to Speed Up, rush past them as well to the shrine.

After this you will be transported in front of a large enemy (Ku I assume). Switch over to Attack Up quickly and finish him off as he can kill you within 3 hits. Once done successfully, you will unlock an achievement and be transported to mainland.

To unlock this achievement as you guessed you have to reach the secret island. From the shrine of Ku turn around and you will see to higher hilly peaks. Go to the highest one and you will see a crystal in sight.



Fall down from there and you will land on an invisible bridge like thing. Follow the crystals as shown below to reach the secret island.









Once you reach the island you will unlock the achievement. You will also find our arch-rival, our first-nemesis Barney calling upon his Dino-Gods and preparing to unleash Jurassic World on Maui.

Continuing onward and back to Roshi you will see there is another island across water which you can cross from Ford. Cross it and you will find a path on the left. Head through that path and turn left again till you see a hut/shrine from far.



Here too you can either dispose of enemies first and then deal with Shrine, or sneakily cut banana from tree, pick it and rush past them to the Shrine. There is also a Taro plantation to the left to help you.





Once you make your offering you will again be transported elsewhere. Here your task is to collect shells and take them to center. Switch to 'Speed Up' and be very quick and precise in this section. Collect the shell by color indicated by flame color and bring it back to flame. Once all 4 are done, you will again be transported to mainland and achievement will unlock.

Now you have to catch a pig and bring it to Shrine. If you choose to dispose the enemies near the shrine before proceeding you can find the Shrine here.



Once you have dealt with enemies, you can find pigs running about here





Use Speed Up and run behind piggies and capture them by pressing E. Once you have the pig, bring it back to shrine



You will again be transported to another region. Quickly right-click and drag circle to be in middle of Health Up and Speed Up as you will need a combo of both in this section. Goal os to reach the flower in front of you but be mindful to be quick as boar behind you will maul you down. Also you will need to stay on stone-paved path as much as you can as outside the path, your health will decrease. Once you have the flower you will be back and achievement will unlock. We are almost near to end!

Now that you have earned favor of all 4 Gods, it is time to fulfill your Kuleana. Head back towards the Shrine of Kanaloa where you got bananas. Opposite (on the map) you will notice a baldy blocking your path whom you have to fight to continue. This guy can be a pain, so keep running around, abusing special attacks and healing with Taro. Once you defeat him a cut-scene will start and you will unlock the achievement.

Congratulations! Here's to 100% completion