Welcome warrior!

This guide is made to aid you in your quest of completing as much of the game as possible. Some of these tasks may be quite straightforward and wont need much additional information. Others, however, might seem impossible at first and require an extra helping hand. Before focusing on achievements I would recommend to first just go and beat ending C (normal play-through). I'm sure you will unlock a lot of achievements on the way.

To unlock this achievement you need to wield Tyr's Flame, the fire sword. You're bound to get this achievement eventually when just playing the game long enough. You can obtain Tyr's Flame by opening four chests in a row without getting hit. The drops will be as follows:

For this one you will need to find Mjolnir's power. Mjolnir's power will grand you the ability to survive one hit without losing gear and kills everything on screen. There is one of these in every area, so two for each world. Most of the times they're hidden in breakable walls. Look for a broken sword lying around, if you find one of those, Mjolnir's power is nearby.

Also see this guide for all locations of Mjolnir's power. Although it might be more fun to try and find them all yourself.

Here's a good example. Notice the broken sword on the ground, indicating Mjolnir's power is nearby.

To unlock this one, you will have to beat the boss of the first world (Jungle of the claw). This boss can be troublesome if you're new to the game, but it's quite easy when you get used to it. Just jump over his shock-wave attack and throw spears at his shield to make a small ladder for yourself. If you do this right you can slash away at his head and beat him in two to three cycles, or one if you have Tyr's flame.

When you are wearing any shield you can block arrows when climbing. You are very likely to get this achievement at the second area of world 1 (Jungle of the claw). Just make sure you are facing the arrow traps with your back when climbing, simply press left or right to change your position while on the rope.

You can only get this achievement when you have the hammer shield equipped. If you hold the spear button, your spear will charge and begin to blink yellow. Throwing the spear in this state will make it pierce multiple enemies. There are some good spots to do this trick in world 1 (Jungle of the claw).

This achievement can be unlocked in world 3 (the blighted lands). Just throw a spear into a green skeleton's shield and hop on. At the end of the first area of world 3 there is actually a skeleton placed just for this trick, facing a wall with a little hole in it. Going to this part is definitely the easiest way to unlock the achievement. By using this trick on him you can actually get across some spikes and open an extra chest.

Now this achievement can be a bit difficult, especially when you're getting used to the controls. Not only do you need to block an arrow using your shield, you also need to be airborne. You're most likely to unlock it in either world 1 (Jungle of the claw) or 2 (city of Arkon). Try and time your jump so you can block spear traps or oysters shooting pearls.

For this achievement you need to collect a warrior spirit. A warrior spirit is an blue flame which will allow you to enter a more difficult version of the next world after defeating the boss. To get this spirit you need to open seven chests in a row without getting hit (six if you have a wooden shield). Collecting Mjolnir's power can be a great help for doing this, as it allows you to take one hit without losing gear.

The Walrus statue is a very rare treasure that can only be collected after opening eleven chest in a row without getting hit. This means that after collecting Tyr's flame and the warrior spirit you will still need to open four more chests. This can be done in any world, only some chests are a bit harder to find or reach than others.

After obtaining a Warrior spirit by opening six chests without losing any gear and beating the level, you get the option to enter the Valkyrie version of the next world. Make sure you take the alternate exit in your home base in order to get there and unlock the achievement.

Make sure to go through the top door. The bottom one will bring you to the normal path.

After finishing the fifth world (Sky knight Armada) you will go to a cutscene where Volgarr approaches Fáfnir's tower and breaks the spell, thus unlocking the achievement. You can even get this when you skip levels.

Ending C is the easiest of the three endings. That being said, it's still a solid challenge that many Vikings fail to complete. To get ending C, you have to play through the game following the path of the crystals. You can use level skips (by going left at the start of a world) as much as you want, as long as you end up killing Fafnir in his tower, you will get this achievement.

Ending B is not that much more difficult than ending C. To get this ending you will have to beat the Valkyrie version of world 6 (Fafnir's tower). This means that you will have to get to world 5 (Sky Knight Armada) and obtain a Warrior spirit and beat the boss. Luckily, you are allowed to skip worlds for this achievement. This means that you can just go left on the beginning of every world, until you come to world 5.

On the end of world 6's Valkyrie version you will jump through the window of Fafnir's tower. When the next area loads, make sure to hold the down button. Doing this will assure you to also get the "That was... unexpected" achievement.

To get ending A you will have to play through the game by choosing the complete path of the Valkyrie. This mean you have to obtain a warrior spirit in the first world and then get to world 7 without running out of lives. If you do this right you will have collected all five key stones. These stones will open up a special portal in your home base after beating Fafnir. When you go through this portal you will arrive in the secret seventh world. After beating this seventh world and the accompanied boss Nidhoggr, you will unlock this achievement.

If you managed to collect a Warrior spirit and enter the Valkyrie version of a world, you will find a key stone at the end of the world, right before the boss. But beware, the warrior spirits you have collected so far will count as lives here. I'd recommend first getting ending C before attempting this.

The key stone at the second world.

If you have taken the path to get to ending B or A (see ending achievements), you will have to climb the outer wall of Fafnir's tower. When you reach the top and jump through the window of Fáfnir's tower, make sure to hold the down button. This will result in immediately killing Fáfnir as you enter the room, thus getting the achievement.

You will unlock this achievement when you enter the secret seventh world. You can only get here by collecting every single boss key stone from the Valkyrie path and beating Fafnir. You will not be able to get here if you skip ahead, so you'll have to play the game from start to finish in one go without running out of warrior spirits.

Impossible to miss if you're aiming for ending A.

This is rather difficult, but certainly not impossible. Especially when you're aiming for ending A or B you will probably unlock this achievement. Pick a world that you're really familiar with or find easy (probably world 1) and keep repeating it until you get through without losing any equipment. Just take your time and make good use of the look ahead function. Note that you can also use Mjolnir's power to help you, because in that case you can survive one hit without losing equipment.

This achievement will unlock if you manage to beat any world in under four minutes. Any of the worlds can be beaten in under four minutes, but the best one to do this on is probably world 1 (Jungle of the claw). A good help is to go to your settings and enable "speed run hud" as well as "toggle look ahead", so you can track your time and anticipate on coming traps/enemies. Try doing anything to shave off seconds by making good use of rolling, jumping, spear throwing etc.

Also, I can recommend searching for some speedruns on Youtube or Twich. Of course you can't recreate those exactly, but there might be some tricks you can use or hadn't thought of.

Not much to say about this one, just keep trying. If you already beat the game you can also skip ahead to the last level by going to the left on every screen. This trick will make it a lot easier.