Heresiarch Grimm

Heresiarch Grimm (Originally Legionthantos) is a welsh born let's player who spends his time doing various games, mainly PC games and ported games. The videos themselves are usually informative and tend to contain a few shenanigans. The shenanigans range from sequence breaking Metroid Zero Mission and Super Metroid up to getting as close to invulnerable as possible in S.T.A.L.K.E.R Clear Sky.

Over the years, the channel has undergone improvements where possible and is still being improved to this day.

The Shenanigans
In almost every game that Heresiarch Grimm has Let's Played there has either been a gimmick or some form of game mechanic abuse for either gain or difficulty. What follows is a list of some Shenanigans that have been used and to what extent:

Starship Troopers - Terran Ascendancy : Self imposed restrictions on weapons as well as trying to hold ground rather than retreat. In levels where the restrictions weren't possible, they were ignored for the duration of the level.

Metroid Zero Mission : Sequence breaking to obtain items such as the Varia suit early and skip a boss by obtaining Super Missiles.

Metroid 2 - Return of Samus : 100% run to obtain the best possible ending.

Super Metroid : Used various techniques such as the Speed Mock Ball to obtain powerups and skip some sections of the game in an effort to obtain the best ending by beating the game fast enough.

DooM 2 - Quake Total Conversion / Chex Quest / Quake 2 Total Conversion / Army of Darkness : By using a DooM engine called Skulltag, the ability to mouse look as well as jump and crouch led to some interesting scenarios.

DooM 2 - Auferstehung : Through the same tricks deployed in the previous DooM WADs, the notoriously bad Auferstehung WAD ended up breaking itself in some rare places.

Hero : Through a strange bug involving death or pausing the game at a certain moment, the final boss was rendered trivial.

Hero Core : By using Auto fire and technically sequence breaking, Hero Core ended up playing slightly differently.

S.T.A.L.K.E.R - Call of Pripyat : Extensive knowledge of the game enables the abuse of certain achievement rewards to give an incredibly dangerous arsenal.

Hitman - Blood Money : Through careful use of ingame mechanics such as the faithful COIN and syringes, a Silent Assassin rank was aimed for on most levels.

Knights of Honor : The mission was to use the Teutonic Knights to capture Jerusalem. The method involved a unit that, because of how game mechanics such as morale worked, could destroy entire armies by just four of them.

S.T.A.L.K.E.R - Clear Sky : Even when the game bugged out and caused interesting situations, especially concerning a Duty Soldier and a ceiling, the artifacts were used in such a way as to be as close to immortality as physically possible.

F.E.A.R - First Encounter Assault Recon : With the lowly Bicycle Kick being able to take out soldiers rather easily, and a slow-mo system that can be used at a moments notice, the game ranges from moments of pure slaughter to being dangerously close to death.

Let's Plays; past, present, future.
There have been many Let's Plays on the YouTube channel and this is a list of them (When a Let's Play is finished, a playlist is created):

COMPLETED

Starship Troopers - Terran Ascendancy

Zone of the Enders - Fist of Mars (Both Path A and Path B)

Killing Floor (Some levels were done, not all and most were single player)

Let's Play Series - Main Metroid Series (Metroid Zero Mission, Metroid 2 - Return of Samus, Super Metroid and Metroid Fusion)

Clive Barker's Jericho

Let's Play Series - DooM Total Conversions (Quake and Quake 2 Total Conversion, Army of Darkness, Auferstehung, Chex Quest)

DooM - The Roguelike

Hero

Hero Core

S.T.A.L.K.E.R - Call of Pripyat

Hitman - Blood Money

NUD

Knights of Honor

S.T.A.L.K.ER - Clear Sky

ONGOING

Let's Play Series - F.E.A.R (F.E.A.R, Extraction Point, Perseus Mandate (blind), F.E.A.R 2 - Project Origin, F.E.A.R 2 - Reborn (blind), F.E.A.R 3 (blind))

POSSIBLY UPCOMING

Metal Gear Rising - Revengeance : Naked Run (No suits, No Sword upgrades / New weapons, No Health or Energy upgrades, No Wigs, No Skills bought).