Keen 4 Bugs
This page lists all the bugs, odd behaviors and unexpected actions that have been discovered in Keen 4.
Well of Wishes bug in God mode
Often, when two Dopefish overlap and God mode is activated (this is accomplished by entering the Well of Wishes in Hard difficulty level), the game starts to get out of free memory, and all animated sprites (i.e. bubbles) get stuck in the game screen instead of disappearing after a certain amount of time. This eventually crashes the game in low-memory environments.
Bad grammar entering the Perilous Pit
When entering The Perilous Pit, the entrance text reads "Keen plummets into the The Perilous Pit" instead of "Keen plummets into the Perilous Pit".
Bad grammar entering the Pyramid of Shadows
When entering the Pyramid of Shadows, the entrance text reads "Keen move silently in the Pyramid of Shadows" instead of "Keen moves silently in the Pyramid of Shadows".
Not so Invisible
Only certain Keen sprites respond to gravity; if Keen is looking up or down, or hanging from a ledge, he is immune to falling. Thus, if Keen does any of these on a Miragia platform, he can stand on it, even when it disappears. If he is looking up/down, if he then stops when the platform is solid, he can stand on the vanished platform for as long as it takes his "bored" animations to start. So if the blocks start disappearing, quickly grab the ledge of one of them and climb onto it again when it reappears.
Miragia platform clipping
There is another glitch relating to the platforms in Miragia. If you jump or fall through a platform block precisely when it is turning solid, it is possible to grab onto the inside edge of the outer blocks. This causes Keen to hang through the center of the platform. This takes a lot of chance to do correctly and can be seen in this video.
Hole in his Head
When Keen is at the top of any pole and facing left, shooting left will display the sprite used for shooting left on a pole, this however is missing a piece of head that is normally covered by the pole, but not at the pole top.
Blue Bird of unhappiness
If you can lure a flying Blue Bird to the right edge of a one tile thick platform (and sometimes walls or thicker platforms), it will get clipped into the platform and not be able to chase after Keen. (God mode helps at least for practice.) It can be freed only by stunning it.
What Lies Beyond
Keen can peek at and past the lower level border under certain circumstances, viz that if the game is saved while he is standing on a moving platform near the level bottom, the screen will be recentered after saving (and whenever the game is loaded), so that he can look down and see not only the level border, but also a bunch of scrambled, random graphics tiles "outside" the level, probably caused by reading memory out of the tile array, resulting in random garbage left by other programs or procedures of the game itself.
The only place this can really be seen is beneath Crystalus, but it works in any other level if platforms are placed right.
In a similar vein, Keen can see what is offscreen by saving his game. This can be done in places like the Pyramid of the Gnosticene Ancients by using God mode and dropping into certain tar pits.
Well of Wishes clipping error
'Air door' trick
When Keen exits any door, he initially does so standing. Keen can thus reenter a door immediately after exiting it. This is true even if there is no solid ground under the door. This was overlooked by the game designers and some 'air doors' have no information plane entry, the game takes this as transporting Keen to (0,0) in the level, which is offscreen and thus lets him exit. If the doors are given a proper value, this can be fixed. Such doors occur in two levels:
In the Cave of the Descendents, go to the lower leftmost part of the map, where are two elevators. Go down to the second one where has a door that teleport you to another on the top of the map. Enter the door then release the up key and immediately press it again and keep it pressed. It will make Keen enter to door in the top and consequently exit the level.
In the very beginning of the Chasm of Chills, fall down and head right. You'll find three small chasms. Drop into the middle one, and jump trough the hidden passage at the right. Keen will fall right in front of a door. Press the up key to enter the door, then release the key and immediately press it again. Keep it pressed. Keen will then enter a door mid-air, in another room, and complete the level.
'Invisible Door' glitch
Similarly to the Air Door glitch there is also that glitch of exiting the level by hitting up while on the moving platform in the secret area of the Border Village. But this time around it is the tile properties of the foreground tiles in that area. They are marked with a flag value of $02 which represents door tiles. Since these tiles have no information plane entry, the game takes this as transporting Keen to (0,0) in the level, which is offscreen and thus lets him exit.
In Lifewater Oasis, when using the F10+J Jump Cheat, if you make Keen hit the ceiling in different places and at different angles, Keen will disappear and randomly reappear somewhere else within the level. In fact, there are at least two places (possibly more) in the ceiling that, if you make Keen jump in these places at the right angles, he will actually reappear in the water where the five Lifewater Flasks are. The interesting thing is that one of these places is right above the highest structure where the big door and the Thundercloud is. If the game designers had created Keen to jump higher or designed the structure to be closer to the ceiling, then it would be possible to take advantage of this bug and get to the Lifewater Flasks without cheating. Unfortunately, once you are there, it is impossible to get back out without cheating. This bug only works when you are at the outside of the level. It does not work in the lower cavern.
Outside the Pyramid of the Forbidden
It is possible to go outside the Pyramid of the Forbidden without using the F10+N clipping cheat. At the beginning of the level, as you are going towards the top of the pyramid where the first Lifewater Flask is, there is a green Dart gun above the flask and there is a small gap in the wall just above the gun. Using F10+G God mode, you can grab onto the ledge where the gap is and it will push you off the screen and out of the pyramid. Then, you save your game and then reload the game you just saved. It will show Keen standing outside the pyramid.
If a creature that normally stays on the ground all the time is somehow forced into the "air", it will appear to spin around like a propeller, without falling down. This is probably because such creatures are programmed to turn and face the opposite direction when they come to a cliff edge, i.e. the next tile is empty air, but when they turn and find that there is "air" on the other side of them, they reverse direction again.
This can be done with Inchworms (in the Pyramid of the Moons) and Poison Slugs (in Sand Yego). In both cases, Keen has to lure the creatures out onto a bridge, and then flip the switch that makes the bridge disappear. When this happens, the normally land-bound creature will find itself in the air, and commence spinning. If a Poison Slug is shot, it will then fall out of the air as per normal. May also work with Arachnuts.
Imaginary pole in The Perilous Pit
In the same room as the Council Members in The Perilous Pit, there is a tile at the right side of the gem-holder which is set to act like a pole even though the tile is empty. Ordering Keen to look down while bypassing the tile will cause him to lag, changing him into his pole-climbing form back and forth into his ordinary running/standing form.
Break the scorebox
In several levels it is possible for Keen to emerge from a door and touch an elder. Since the sprite for Keen appears before the screen moves to the new location, the elder message appears over the door Keen entered.
Due to how Keen moves between doors (As an invisible sprite) the function refreshing the scorebox is not called, meaning that it is blank until Keen does something to change this (Dying, exiting the level, getting something...) This takes a lot of chance to do correctly and can be seen in this video.
Berkeloids flame through walls
Beating levels while dead
It's possible to cheat past several of the levels in Keen 4 by dying near the right edge of the map, saving immediately, loading and letting Keen fall off the edge of the screen. This will cost you one Keen per level, obviously. This may be done, for example, in the Pyramid of the Moons as follows:
- Without obtaining the gold keygem, stand by the exit door.
- Let the Arachnut touch you so Keen dies. Hit Escape immediately, before the "You didn't make it past..." dialogue appears.
- Save your game.
- Load your game. Provided Keen doesn't repeat-die by touching the Arachnut again, you will win the level when Keen reaches the right edge of the screen.
Bounder Pole Door Glitch
The player needs to reside Keen on the pole, near the Bounder, but somewhat into the floor. Eventually the Bounder is expected to push the player down. Afterwards Keen must not touch any pole but go through that door, which then exists the level.
This happens because various creatures are represented by object. Each such object has a few variable properties, including y-Direction. In the case of the Keen player object this direction is usually set to 1 (e.g., while standing, jumping or falling down). But it may change while using a pole ( -1 while moving up, 0 while standing still, 1 while moving down) and if something unexpectedly pushes it out of the pole, the y-Direction may keep its older value until you try to make it go through a door. When it's 0 or -1, this is when the glitch is reproduced.
Flags clipping in front of Scorebox
Both the flipping and sitting Flags use a foreground variable of 3, putting them in front of all tiles at all times. Sometimes this can cause issues for eg. on the Worldmap when the Flags will appear in front of the scorebox. This is because the scorebox has the same foreground behavior to ensure it appears over all tiles. The scorebox is nearly always spawned first, putting it higher up the foreground list, meaning a sprite 'equal' to it will appear in front.
Not So Impossible Bullet
The secret area of Border Village contains the only platform in the game that falls below the level border and disappears. Let Keen ride it down, don't jump and wait until the platform has gone off-screen. Then shoot upwards, Keen will ride the bullet like when using the Impossible Bullet Trick in Keen 6.