Differences

This section lists the differences between the HD and non-HD games (Tourist difficulty assumed).

General

Physics

You no longer gain extra altitude when jumping up slopes.
The speed boost when jumping down slopes is smaller.
It is much easier to stand on top of enemies.
You can prevent falling underwater by holding jump.
You cannot get hit by cannon balls anymore.
Jumping on candles is now possible.
While walking down stairs in non-HD, you will be airborne and unable to jump. In HD this is not the case.
"Swimming" when out of bounds in certain spots is no longer possible.

Boosts and jumps

Many boosts and jumps which require you to stand on enemies are only possible in HD.
Single bull boosts are much weaker.
Kleer boosts are stronger.
Fish boosts are more effective.
Kamikaze boosts have been removed.
Cannon jumping is not possible.
Higher difficulties no longer increase the power of the boosts.

Enemies

Enemies now have different textures when damaged.
Beheaded Rocketeer/Firecracker have new melee weapons.
Floating Gnaars do no longer follow you vertically if jumping on them.
Kleers now always charge at you if close enough, instead of running next to you and slashing.
Harpies do not get knocked back excessively when shot anymore.
Harpies only have the gore explosion death animation.
Highlander Aludran Reptiloids have higher health (20 rockets to 14 in non-HD).
The fireballs of the Highlander Aludran Reptiloids can now be destroyed with rockets.
The Electro-Fish's attack has longer range.
Large Lava Golems have higher health (29 uncharged cannon balls to 23 in non-HD).

Weapons

Colt/twin colts fire 30%/20% slower.
Minigun does double damage, but fires at half the speed.
Rocket Launcher ammo contains 8 rockets instead of 5.
Grenade Launcher fires up to 50% faster.
Grenades now deal self damage.
Fully charged Cannon fires 15% faster.
Uncharged Cannon fires up to 135% faster.
Switching weapons is much faster.
In non-HD there is a few frames of lag before projectiles appear, in HD they appear instantly (Grenade Launcher, Laser, Cannon).

The First Encounter

Tomb of Ramses III

You can no longer jump over the trigger that makes the wall move down in the corridor after the Gnaars.
In non-HD you have to jump up a steep slope right before the final room. In HD a candle has been added which simplifies the jump.

Dunes

There are now three Werebulls instead of two in the starting area.
You can no longer skip the arena battle by getting pushed into the door.

Suburbs

A Minor Biomechanoid has been added close to the starting point. Killing it spawns a Kleer.
More geometry that you can get stuck on has been added to the well and the secret platform is bigger.

Sewers

By getting boosted by a Kleer you can get past the moving wall before the final area without having to press the button.

Metropolis

You can get out of the level already in the second area by jumping on a Harpy.

Alley of the Sphinxes

You can no longer skip the arena battle by getting pushed into the door.

Karnak

The spawn timing of some enemies in the arena battle has changed.

The Great Pyramid

The waiting time for the door to open is now ~2:10 instead of ~2:00.

Glitches and tricks

Strafe jumping

Strafe jumping increases your movement speed by up to 10%. Simply jump and tap the left and right movement keys repeatedly while in the air. You will gain small speed boosts which depend on how quickly you tap the movement keys, although tapping too quickly will nullify the effect.

Harpy jumping and flying

Just like with the Floating Gnaar, it is possible to reach any height with a Harpy. First make it fly into a wall or stun it (only works on 30 FPS), then jump on to its back and scroll wheel jump. It works the same way as with the Floating Gnaar, except the Harpy will continuously kick you while you are standing on it, possibly canceling out the jumps. The kicking attacks can in turn be used to gain extremely fast horizontal speed. You will start floating towards the kicking direction, and for each consecutive kick, your speed will increase. However, you will need to move towards the center of the Harpy after every few kicks to adjust your position, otherwise you will be knocked off, although the higher FPS you play on, the harder it is to get knocked off. By combining the jumping and the horizontal boost you can basically fly around the levels, and you can instantly fall off by crouching.

Floating with Floating Gnaars

Unlike in non-HD, the Floating Gnaars do not float higher if you simply keep jumping on them. However, you can trick them to do so by jumping horizontally out of their attacking range, making them move towards you to attack. By moving towards them and landing on them again, you will be floating horizontally towards the opposite direction of where you were attacked from. It is possible to float faster by having a second Floating Gnaar push on the other one. If you scroll wheel jump after performing the horizontal jump, the Floating Gnaar will keep following you upwards, meaning you can also quickly reach any height (easier on a high FPS). Finally, you can make them sink by crouching while standing on them.

Bull jumping and riding

Bull jumping is performed by standing on top of a Werebull and jumping when it is about to attack. The altitude reached is timing dependent, but a perfect bull jump gives roughly the same height as a standard bull boost in non-HD. Getting launched by two Werebulls throws you even higher into the air (double bull jumping). It is also possible to travel with the speed of a Werebull by getting on top of one while it is running. Usually it does not work if on even ground with the Werebull, so it is easier to do when it comes charging down a hill. After a while it will halt in order to attack you, but it is possible to cancel out the attack by jumping out of its attack range and landing back on again. You can also let its attack hit you while you jump to perform a boosted bull jump.

Clipping through the ground

There is a glitch which makes it possible to clip through the ground by pressing crouch as you are about to land from being airborne. The glitch is dependent on frame rate, your altitude and speed, and the thickness of the ground geometry. The lower the frame rate and the longer you fall as well as the thinner geometry, the higher the chances of clipping through the ground. It is possible to do it on 60 FPS in order to combine it with Harpy flying, but it does rely on extreme falling heights, thus 30 FPS is required for shorter distances.

Only works on an older version in TSE as it was patched out.

Object boosting

Due to a collision glitch, certain objects are able to boost you when you interact with them in a certain way, sending you great distances at extremely fast speeds. In order for the glitch to work, an FPS of roughly 200 is required, and any higher FPS does not appear to increase the power of the boost.

Crouch swimming

Swim faster by holding either crouch while on the floor, or jump while at the roof. You will swim about twice as fast, but will be unable to turn while doing it.

Turbo Laser

By binding primary fire to the mouse wheel, the Lasergun can fire three times as fast on 60 FPS (dealing 600 DPS - second only to Cannon), or even faster on higher FPS.