Turns out we can skip all levels completely except the lobby and roof by CLDs. This is too broken to be entertaining.
In general, the weapon strip skip is possible if you run fast enough at 20 fps. 1000 ups will definitely work (we can skip by quickgaussing later).
In twhl-lobby.bsp, while the screen is black, we can start moving forward to start the speech. There are two possible ways to complete this map. First, simply stand on the garbage can beside the vending machine, and jump towards the vent, thus skipping the need to get the keycard. Alternatively, we can skip the weapon strip by bringing a box, jumping on it, then jump onto the door while it’s in the opened position. This should save some time in the next room as we’ll be able to break things right away with the crowbar, but then this requires taking some time to grab the keycard and moving the box.
In base-2much, if we get to keep the crowbar and glock from the previous map, we can do qws with crowbar and glock to break stuff. Otherwise, we have to wait for the music to start playing to break the glass, which takes about 4 seconds, and grab the crowbar from the crowded storage room. The security override button can be pressed from outside through the wall.
The door exiting the music room can be opened by jumping onto the glass and touching the door. This must be done right: if we instead “slide up” of the glass, for example, then it will not work.
Without crowbar from before:
In drorange, at the beginning we can use a box through the wall to boost towards the scientist to quickly trigger his speech. It is possible to block the first door so that it doesn’t fully close, leaving just enough room for us. This can be done by pushing the scientist, though this will take a long time. Then we might be able to object boost using the chair to gain speed to rush towards the weapon strip. Though this may not actually work since the space is tight. At any rate, we might be able to use the chair in the crowbar room through the wall to boost around. We can object boost to maximum speed using the box through the final vent, so that we might be able to rush through the weapon strip.
In jeffmod, we can object boost all the way using the (only?) movable chair at the front desk. The weapon strip can be skipped using the chair as well. Though this is not that useful if all we have is the crowbar, as the crowbar can be readily accessible in the next map.
In urblab-floor, we can press the button to expose the crystal from outside the room, so we don’t need to wait for the door to open (which takes a long time).
It may be able to get the grunt to open the entrance door to the grunt area after we pressed the button and going back.
In nine, there are several pushable chair that can be used for object boosting, and they can be moved everywhere. It may be possible to open the door, press the laptop, then rush back through the door while it’s still open. It opens for about 4 seconds.
In malle-base, the lasers can sometimes be skipped. The final two fast moving lasers sometimes will glitch out if we save load. The first button can be punched through the wall where the turret is. Unfortunately the final button cannot be pressed through walls without going through the intended route.
In twhltower_jessie, we can use the exit door of the gauss room right from the start, so that once we get the gauss the door will already be opened. After pushing the box in the final room to the right position, when we’re going back we should start object boosting with the box as soon as we encounter it in the previous rooms, meanwhile positioning it so that it ends up nearing the security override button in the other room. After pressing the security override, we should then position the box along the walls, so that we can use it through the wall inside the gauss room.
It is actually possible to not use the box to press the security override, though this means not being able to object boost. It is not clear which route is faster. Since quickgauss works in this mod, we are able to skip the weapon strip, assuming we do not selfgauss ourselves. It is very easy to selfgauss ourselves, so the solution is to duck and shoot the very edge of the yellow stripes.
In twhltower_tjb, the glass of the room storing the key can be broken with gauss, so we don’t have to wait for the door to open.
In tma_floor, the door to the right at the entrance is supposed to be locked, but we can use the button through the wall at the opposite side, thus accessing the centre room immediately. Though it’s not clear if this saves time. Also, there is no need to wait/kill the scientist to open the door to the security room. We can place all keycards and press the button through the wall. We should quickgauss the room with a lot of headcrabs through the wall, thereby kill all of them and the breakable wall at once by gauss punching. If it is faster to grab the third keycard through the breakable wall, we can do so, or we can just quickgauss to skip the electricity to get to the third room. The chair in the first room is movable with lower frame rates, though we can’t bring it out of the room. Since this map is the last time we get to use gauss, we can afford doing gauss rapid fire to gib potentially obstructing enemies.
base_strider has virtually no skips or tricks to it. The intended route is the only way to play this map. Unfortunately too, the map strips your weapons (most crucially gauss) even if you managed to skip the weapon strip point. Note that we are able to move even while the camera is showing the exit door opening.
Note that a key (not the final key) can be found in the first room with cabinets, before the room with a gong in it. This key disables the cameras in most of the rooms but not the room with gong. You still need the key in the room with gong. The first key is not strictly necessary, as you can crawl through the two opposite facing camera very carefully without triggering them. And it might be faster not to grab the first key.
In twhl-roof, we can jump on top of the grunt and thus able to walk on the roof. Though this only works on roof sections where the height is lower. Alternatively, we can jump on one of the green boxes in the first room, then jump on one of the grunts, then jump out of the room onto the roof. Once we grab the RPG, the portal will open. However because we didn’t activate the dynamite, we can’t get out of the room without damage boosting with the RPG.