This page focuses on 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.
• In non-HD it is possible to get out of bounds in some of the levels and noclip to the exit. In HD you will just fall down until you are teleported back into the level.

Boosts and jumps

• Single bull boosts are much weaker, but getting hit by many bulls simultaneously may result in insane boosts.
• Bull jumping, bull riding, and super Kleer jumping are only possible in HD (see the Tricks section).
• Kleer boosts are stronger.
• Fish boosts are more effective.
• Kamikaze boosts have been removed.
• Harpy jumping is now possible.
• 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 melee attacking.
• 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 hit by the Rocket Launcher.
• 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 twice as slow.
• Rocket Launcher ammo gives 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 the shots 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 door move down.
• 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 in the beginning. 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 without having to press the button.

Metropolis

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

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.

Tricks

Bull jumping

Performed by standing on top of a bull 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 bulls throws you even higher into the air (double bull jumping).

Bull riding

The fastest single boost in the game. Just get on top of a Werebull while it is running. Usually does not work if on even ground with the Werebull, but easy to do if it comes charging down a hill. After a while it will stop to attack you, but it is possible to cancel out the attack by jumping. You can also let its attack hit you while you jump to perform a boosted bull jump.

Super Kleer jump

Involves riding on multiple Kleers to build up enough momentum to get boosted up a sloped wall. Can result in altitudes as high as a strong cannon jump in non-HD.

Floating Gnaar jump

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. Even better, if you scroll wheel jump after doing this they will keep following you upwards, meaning you can reach any height.

Turbo Laser

Bind primary fire to mouse wheel and the Lasergun can fire three times as fast, dealing 600 DPS (second only to Cannon).