Bastion/Basic Mechanics

Movement

It is important to set your control style to "Mason-Style" (mouse and keyboard, not using WASD). With mouse controls, rolling while holding down your mouse button causes you to move about 30% faster than in other control styles, because the game adds the speed of walking to your roll travel distance.

The fastest movement method in Bastion is rolling (called Evade in-game, with Space being the default keybind), just because it is much faster than walking. Throughout the entire speedrun you want to roll as much as possible - and since you can't buffer the roll input (if you press roll while in the animation of your previous roll, you won't roll again), the best way to achieve that is chaining your rolls: pressing roll as soon as the animation for the previous one ends. Having a good rhythm to your rolls helps optimize your movement.

A crucial part of a Bastion speedrun is avoiding falls. In Bastion, most of the ground in every level forms up as you approach it. The problem with that is that the levels very often form more slowly than you can move through them, which might cause you to outpace the terrain and fall, wasting about 2.5 seconds. This can be avoided by slowing down your movement by walking instead of rolling. More advanced players will curve their roll paths at points where the ground forms slwoly so that they move faster, but take a less direct route - in total, you can move more quickly this way, but you must have good mouse control.

Experience and Levels

Killing enemies, picking up certain items(cores, mementos) or Blue/Black Tonics when you are already full on this type of a Tonic(a Blue Tonic will first heal you if your HP isn't already full) will make you gain experience. Once you fill out the experience bar, the Kid will level up, causing a couple of things to happen: Your HP and both types of Tonics will be restored fully, the Kid will do a short animation of leveling up(causing you to lose control for a while), and an explosion around the Kid will cause enemies nearby to take a lot of damage. This has some uses in All Story Levels runs and is knowledge you need to have to understand the any% experience route.

Fragments

Fragments are "pieces of the Old World" and they function as currency in the game to pay for Forge upgrades or recovering missed items in the Lost and Found. You can find them almost everywhere well as receive for completing some challenges. In all current routes they are completely useless since NG+ already has everything it needs in its file and NG doesn't ever buy anything.

Cores, Shards and Game Progression

Cores and Shards are objects you can find in some levels that allow you to unlock building slots in the Bastion, unlock levels and are necessary to complete the game. Whenever you put one of the first six Cores into the Bastion Monument, you will unlock a building slot and every time you store one of the first six Shards, you will be allowed to upgrade one of the existing buildings. One of the most important things to understand about the any% route is that to complete the game, you don't need to complete the last level of the game - you merely need to store 7 Shards and 7 Cores. After using the Monument for the 14th time, you will trigger a screen transition that will take you to the Heart of the Bastion, letting you select an ending and end the run.

Buildings

You can find some of these buildings in certain levels(most notably in the Wharf District where you are forced to open the Arsenal and the Distillery) as well as build them in the Bastion to be able to access them between levels.

• Arsenal - lets you switch out weapons and skills
• Forge - weapon upgrades
• Lost-and-Found - recovering missed items from the completed levels
• Memorial - awards Fragments for Completing Vigils(challenges)
• Shrine - allows you to enable Idols(increasing the difficulty of the game)
• Distillery - equipping Spirits that provide passive buffs
• The only buildings used in current speedrun routes are the Arsenal and the Distillery.

Weapons, Skills and Spirits

Rather than a comprehensive description of every weapon/skill/spirit in Bastion, this will only include some info on the ones that are or were useful in speedruns:

Weapons

• Cael Hammer - a weapon you can't skip. Has three attacks, a moving attack and two stationary attacks that have longer animations but deal more damage.
• Fang Repeater - an overall pretty bad ranged weapon that we pick up because doing so doesn't waste any time at all and it is useful in some places of the Wharf District.
• Brusher's Pike - found in the Roathus Lagoon, picked up for its higher damage output.
• Scrap Musket - found in Cinderbrick Fort, a much better ranged weapon than the Fang Repeater that you can get quite early in the game. Useful for clearing out obstacles and for executing a quick kill on Mr. Lunky.
• Galleon Mortar - found in Mount Zand, a very slow to use ranged weapon that is useful for killing Rattletails - an enemy that has to be killed in Urzendra Gate that sometimes turns invulnerable to anything but Grenades and Mortar shots - and clearing out some debris in the Zulten's Hollow, since at the end of the game it deals much more damage than the unupgraded Scrap Musket.

Skills

• Sneaky Decoy - picked up in the Roathus Lagoon, lures enemies to the decoy and turns your next attack into a guaranteed critical hit.
• Whirlwind - picked up in the Wharf District, helps kill the foreman in the Workmen Ward in NG categories.
• Trip Mine - found in the Melting Pot. Works about as you would expect a mine to work. Limited usefulness, but picked up in the NG ASL route.
• Hand Grenade - picked up in Sundown Path, a thrown weapon with an extremely high damage AoE explosion. Locking on to a target before throwing one is almost obligatory, as this way the grenade will fly in a lower arc and hit much faster.
• Pike Vault - only used for skipping parts of levels, never for damage. Read more here.

Spirits

• Werewhisky - +100% Critical hit chance when below 33% Health. Critical in some levels.
• Cham-Pain - +25% Damage, -1 Chance to Carry on if Defeated. Only available in New Game Plus mode, used to kill some bosses faster and to save time during the Ura Invasion Skip.
• Black Rye - +2 Black Tonic Capacity. No longer used in any category; used to be required to complete Prosper Bluff in the fastest way.

The Battering Ram

In the last part of the Tazal Terminals, you're forced to use a slow weapon called the Battering Ram. This prevents you from rolling and using any other weapons or skills. Your only available actions at that point become:

Ground slam - the primary attack, lasts 63 frames, kills everything close to you.

Forward swing - secondary attack, 56 frames long, kills enemies in a small area in front of the Kid. Notice that it's only 7 frames faster than the ground slam, therefore it's only worth using it when a ground slam wouldn't kill any extra relevant enemies.

Shield - http://www.twitch.tv/lawyerdogsr/c/2436288

The special attack - clears out every enemy on the screen. Very slow to do but worth using with a lot of enemies around.

Load screens

At the start of every level and after every screen transition that has a loading screen, the Kid's HP and Tonics will be fully restored. This is only important in certain levels, and most of the time means that there is a rarely reason to use Tonics conservatively or worry about your health too much.

Freeze Frames

Every time you hit an object or an enemy with a melee weapon, the Kid remains frozen for a couple of frames for each object that you hit. This makes it important to avoid hitting anything that you don't need to kill with your melee weapons.

Recovering

Some effects in the game, such as Skybridges and Queen Anne, will knock the Kid up into the air. During this you can press Evade to roll mid-air, which in turn allows you to perform some minor skips and save time.