Didn't seem to already be a topic for it, so I figured I'd start one, especially given that custom level designers need to be aware of some of these (as not only are some of them backroute risks, but some of them can interfere with the levels working as intended).
Unless mentioned otherwise, assume the glitch is only confirmed on the PC version.
Glitch List
Physics GlitchesBuilder Collision Inconsistency - If a builder is 1/4 block below a flat surface, such that his next brick would be placed immediately on the surface (not 1/4 height above it), he will stop building if the surface is at a partial block height (and continue walking
forwards), but place his brick and continue if the surface is at a full block height.
It appears that on console versions, he always continues building in such a case.Dig Through Dangerous Blocks - If a digger digs through a block that's above a water / electrified block, but the water / electrified block is not marked as steel, the digger will continue to dig through said block unharmed. Any lemming that later passes through the dangerous block will die, though, even after it has been fully removed.
Confirmed on all versions of the game.Extra Destruction Glitch, Variant A - A basher that begins bashing from 1/4 block height will take out three slices vertically, instead of the usual two. Debatable if this is a glitch or just a mechanics quirk.
Extra Destruction Glitch, Variant B - On levels which trigger, or are close to triggering, the missing faces glitch (see under comsetic glitches below), sometimes destructive skills will remove an entire block instead of just certain segments of it. This is inverted with the Bomber though, who under the same conditions will not destroy
anything.
Failed Assignment Glitch - If you assign most skills to a climber immediately before they hit a wall (frame-perfect), or while they're bashing or mining a wall (not walking between blocks
as a basher / miner), the skill will be consumed but the lemming will just start climbing the wall. One weird case is that this glitch is triggered when assigning a basher to a miner, but not when assigning a miner to a basher. When done with a non-climber, the lemming will usually turn around and then perform the skill as normal at the next suitable boundary. This does not always work; the direction the lemming is facing (relative to the internal coordinate planes) is a likely factor.
Infinite Dig Glitch - This is a console-exclusive extension of the Dig Through Dangerous Blocks glitch above. Should there be a block at the very bottom of the level that fits the criteria for that glitch, the lemming will dig on the block forever (without moving further downwards or removing any terrain; just stuck in one position).
(Video) Confirmed on both Playstation and Saturn versions of the game; does NOT occur on PC.Jump Glitch - If a faller, during the time they have forwards momentum, hits a block face, they will immediately jump to the top of that block, even if it's higher than a lemming can usually step up. From there they can further step up the normal 1/4 block height.
This glitch is PC-exclusive.Miner Height Glitch - If a miner is started on top of a builder bridge, at a full block height position, the first destruction segment will be placed one block segment higher than usual.
Replay Release Rate Glitch - If a level is played, then the minimum release rate is modified in the level file, and the level is restarted, the new minimum release rate is not enforced during the replay. If the user interrupts the replay, they can increase the release rate to any point between the current and minimum value, but cannot decrease it while it's below (or at) the minimum. Since this won't happen (outside of cases of cheating) while playing levels normally, it's only really relevant while playtesting your own levels.
Slide Glitch - An extension of the jump glitch above. If the jump glitch is used to make a climber jump, and there's solid blocks immediately above the block face that's hit (both above the lemming and above the block); after jumping, the lemming will climb through the solid blocks (multiple layers of them, if applicable) and come out the top. If there is an odd number of blocks above him, he'll face the opposite direction than he did before; otherwise, he'll face the same direction. It appears that whether or not this glitch actually triggers may depend how far up the block the lemming is when the jump glitch is triggered.
This glitch is PC-exclusive.Stuck Digger Glitch - Assign a digger to a lemming between two blockers (at each side of the same block). The lemming will register as a "digger", but will never actually start digging. I assume if you were to somehow remove the blockers without removing the terrain underneath the digger, he would then start digging as normal.
Transporter Bomber Glitch - If a bomber's countdown runs out and he explodes while in transit via a spring, damage to terrain sometimes (exact cause unknown) occurs near the spring that launched him, not near his current position. This glitch also occurs with rope slides. This does not occur with trampolines; bombers on those explode at their current location (after falling a bit during the ohno animation, that is). In the case of teleporters, cosmetic oddities occur but the destruction always takes place where the lemming visually appears to be at the time of detonation. The only official levels where this can be set up without the nuke (which may make it hard to see the effects), are Richochet (spring), Death Slide (rope slide) and Final Maze (spring). In the case of Ricochet, you must use builders to create terrain to see the effect with. The teleporter effects can be seen in Tower of Lemlab, by taking a slightly unintended route to get to the bottom with the bomber
and at least one builder remaining (with the builder only being used to confirm the location of destruction effects; you don't need it if you just want to see the cosmetic effects).
Cosmetic GlitchesMiner Animation Glitch - When a miner is assigned to a lemming, the lemming retains its current animation until it reaches the edge of the block - this can be done easily with a builder (any of the three builder-related animations - walking builder, brick-placing builder or shrugger) or a digger, and with a bit more effort can also be done with a basher. This glitch does
not occur with the basher, which correctly resets the animation to "walking" until the block edge is encountered.
Missing Faces Glitch - If a level has too many visible block faces, some of them will not be rendered (but will still function as if they were there). This is perhaps more of an engine limitation than a glitch as such; looking at official level data shows that active efforts were made on some levels to mitigate the impact of this glitch, and there is a byte in the level data that can be increased to allow more faces before the glitch occurs (although only to a certain point).
Missing Pyramid Textures - This is more to do with corrupt copies of the game than an actual game glitch, but the majority of copies found nowdays have this corruption so I'm listing it here. Due to a corrupt TEXTURE.000 file, some copies of the game black out most of the textures on levels 30, 34, 40 and 64. The other two pyramid levels use TEXTURE.010 instead so are unaffected.
L3DUtils has a patch to fix this bug.
Replay Camera Glitch - Similar to the replay release rate glitch above, the same lack of bounds checking is also applied to camera movements. This can allow the camera to move outside the normal boundaries (which will result in a crash if it goes below the bottom of the level, although all other boundary exceeds do not cause any issues, and the camera will snap back inside the boundaries if / when the replay is interrupted), or to move through solid blocks.
See Through Walls - Sometimes, you can see through a wall by rotating the camera, while using virtual lemming on a blocker or turner placed against the wall. It's also possible that if the camera is moved while paused, it may pass through walls when replaying your actions, with much the same effect.
Transparent Destruction Mask - If a basher or miner (presumably a digger too, but haven't tested this) is destroying a block that has transparency on some/all faces, the destruction overlay will turn segments of the texture transparent, rather than black.
Misc GlitchesCD Music Fails To Loop - On the PC version, after a CD audio track completes, background music goes silent until either it's turned off and on again, or gameplay finishes. For some reason, this bug does not occur when using DOSBox's audio CD emulation with CUE + ISO + OGG files (but does when using DOSBox with a physical disc or a virtual drive from an external application).
This bug is confirmed to occur ONLY on the PC version.CD / Soundcard Music Discrepancy - Many levels have inconsistencies in which music they play, depending on whether the player is using CD audio or another type of music. Levels that use the standard track on soundcard / MIDI are unaffected, but levels that use the alternate track will instead get the standard track on CD audio, while those that use the remixed version of the standard track will get the alternate track on CD audio (the remix version doesn't exist in CD audio, but it would be far more logical to play the standard track here).
L3DUtils has a patch to fix this bug.
Nuke Activation Glitch - It's very difficult to activate the nuke using the UI icon (which requires a double-click). Other means of activating the nuke (running out of time, or Alt+Q) do not have this issue.