I can't think of anything clever to say, so here they are...

14000-141FF Level pointer table

Level addresses
14200: 0-1
142C8: 0-2
143A1: 0-3
14453: 0-4
144D2: 1-1
145C1: 1-2
14726: 1-3
14809: 1-4
1491B: 1-5
149F0: 1-6
14ABD: 1-7
14BB9: 1-8
14C76: 2-1
14E1D: 2-2
14F61: 2-3
15076: 2-4
1515D: 2-5
152BC: 2-6
15447: 2-7
15630: 2-8
15753: 2-9
1583D: 2-10
159BE: 2-11
15B46: 2-12
15C14: 3-1
15DA4: 3-2
15F3B: 3-3
160A1: 3-4
1624B: 3-5
163C7: 3-6
164AD: 3-7
16613: 3-8
16773: 4-1
16919: 4-2
16A4A: 4-3
16BDA: 4-4
16D29: 4-5
16EAB: 4-6
170A6: 4-7
172B0: 4-8
173AB: 4-9
175AD: 4-10
1782D: 4-11
17A56: 4-12
17B64: 5-1
18000: 5-2
18181: 5-3
183AC: 5-4
184AC: 5-5
18589: 5-6
18741: 5-7
188C5: 5-8
18A19: 5-9
18C25: 5-10
18D54: 5-11
18EC8: 5-12
18FCE: 6-1
190D9: 6-2
19235: 6-3
193E5: 6-4
19504: 6-5
1965F: 6-6
1979B: 6-7
199B7: 6-8
19A8C: 7-1
19C42: 7-2
19D9A: 7-3
19F33: 7-4
1A0AD: 7-5
1A1FC: 7-6
1A38D: 7-7
1A555: 7-8
1A6D8: 7-9
1A8C8: 7-10
1AA4E: 7-11
1ABDA: 7-12
1ACBF: 8-1
1AE78: 8-2
1AFFB: 8-3
1B1A1: 8-4
48000: 8-5
48188: 8-6
483A1: 8-7
48575: 8-8
48694: 8-9
48864: 8-10
489B7: 8-11
48B18: 8-12
48C83: 8-13
48E21: 8-14
4908F: 8-15
49294: 8-16
493B6: 9-1
49506: 9-2
4966F: 9-3
4985A: 9-4
4998A: 9-5
49ACA: 9-6
49C5A: 9-7
49D84: 9-8
49E32: 9-9
49ED6: Similar to 9-9, but with a mouse circling the center platform(unused?)
49F7D: Similar to 9-9, but with mice circling the left and right platforms(unused?)
4A02C: Similar to 9-9, but with fast mice circling the left and right platforms(unused?)
4A0DF: Similar to 0-1, but with tower tileset(unused)
4A1B2: Bare room with an unreachable platform in the upper left...(unused)

The following were tested on Stage 0-1:
Level Header Info
Byte 1 [00]: Level Dimensions
00: 160x144
01: 240x224
02: 160x224
03: 240x144

Byte 2 [05]: Music
Byte 3 [00]: Tileset
Bytes 4-5 [64 00]: Time Limit

Music Values:
00: No Music
01: Time's almost up!
02: Temporary Bridge/Ladder/Spring active
03: 30 seconds remain...
04: Pauline abducted again...
05: DK Arcade Level 1
06: DK Arcade Level 2
07: Big City
08: Forest
09: Ship
0A: Jungle
0B: Desert
0C: Desert 2
0D: Airplane
0E: Iceberg
0F: Rocky Valley
10: Tower
11: Tower 2
12: 1-3
13: Spooky
14: 1-7
15: Monkey Stage
16: Dangerous
17: Rocky Valley 2
18: 1-2
19: Battle 3
1A: Battle 1 (1-4)
1B: Battle 2 (1-8)
1C: 9-8
1D: 9-9

Tileset Values:
00: Classic Girder 1
01: Airplane 1
02: Iceberg 1
03: Forest 1
04: Rocky Valley 1
05: Ship 1
06: Desert 1
07: Airplane 2
08: Tower 1
09: Clouds 1
0A: Rocky Valley 2
0B: Desert 2
0C: Big City 1
0D: Ship 2
0E: Jungle 1
0F: Tower 2
10: Classic Girder 2(no visible difference from 00)
11: Airplane 3
12: Iceberg 2
13: Forest 2
14: Rocky Valley 3
15: Ship 3
16: Desert 3
17: Airplane 4
18: Tower 3
19: Clouds 2
1A: Rocky Valley 4
1B: Desert 4
1C: Big City 2
1D: Ship 4
1E: Jungle 2
1F: Tower 4
20: Classic Girder 3
21: Giant Donkey Kong Battle

Tile/object commands (incomplete)
07: Whole ladder
08: Climbing pole
09: Conveyor belt, left
0A: Conveyor belt, right
0B: Solid girder platform
0C: Vertical orange line(bg)
0D: Horizontal orange line(bg)
0E: Diagonal orange line(tl-br)
0F: Diagonal orange line(bl-tr)
18: Springboard from block
20: Enemy-activated lever
25: Poison Mushroom
40: seed-spitting Jungle plant, faces left
41: seed-spitting Jungle plant, faces right
42: Boiling lava tiles
43: Falling platform
45: 2UP heart
4B: Locked Door(fake?)
51: Ladder
52: Panser-generating ground
53: Pauline's parasol
5D: Springboard
60: X tile
62: X tile
65: Pauline's hat
75: Temporary block
76: Unused block?
77: Spring block
78: ? block
79: Locked Door
B5: Mechanical cannon; faces right
C4: Super Hammer

Sprite commands
38: Fireball (Stage 0-4)
3A: Donkey Kong; throws crocodiles (2-4)
3C: Pterodactyl
3D: Bird, glitches up game for unknown reason
3E: Spark, crashes game if not on line
3F: Rolling barrel, stationary
44: Pie Factory Donkey Kong (0-2)
46: Pie, stationary
47: Crushing stone
48: Octopus
4D: Squid
4E: Mario-eating fish
4F: Bat
50: Biting Walrus
54: Platform, moves up and to the right(likely line-guided)
57: Hammer
58: Bone-throwing skull
5A: Hermit Crab
5B: Mario holding a hammer-WHAT?!
5C: Oil drum flames(glitched if not spawned by barrels)
5E: Donkey Kong; spawns fireballs (0-4)
64: Basic walking enemy
6E: Donkey Kong; throws non-carryable barrels (0-1, 9-5)
74: Elevator platform
7A: Giant Donkey Kong! (9-9)
7C: Flame
7D: ?
7E: Burrowing "Panser" (crashes game)
7F: Mario's starting point
80: Wall-walking mouse/ladybug/walrus/armadillo, depending on tileset
82: Weird Helmet thing
84: Floating iceberg platform
86: Wind-up toy/Penguin/Tree/Cactus/Scuba diver/Mummy/Pharaoh/Armored guy/Robot/Zombie, depending on tileset
88: Knight
8A: Donkey Kong; throws Egyptian/rock guys (5-12, 8-16)
8E: Wind
90: Donkey Kong; throws 1 spring (0-3, 2-8, 4-4)
92: Donkey Kong; throws non-carryable barrels grabbed from both sides (5-8, 9-2)
94: Monkey
96: Falling icicle
98: Wall-walking flame/Pointed zapper/Spiked bug/Porcupine/Scorpion/Skull monster, depending on tileset
9A: Donkey Kong; shakes the ground, causing an avalanche of objects (1-4, 5-4, 7-8, 9-1)
9C: Mario w/hand lifted up?
9D: Fruit
A0: Rolling Cockroach
A2: Frog
A4: Donkey Kong; throws boulders (8-8, 8-12)
A6: Donkey Kong; does nothing (3-4, 6-4, 7-4, 8-4, 9-4, 9-6)
A8: Donkey Kong Jr.; runs from side of screen and throws poison mushrooms
AA: Donkey Kong; drops poison mushrooms (4-8, 9-3, 9-7)
AC: Trash can monster
AE: Trash can
B0: Block creature
B6: Klaptrap
B8: Lock icon
BA: Oil can
BE: Donkey Kong; throws barrels that can be kicked and picked up (4-12, 9-8)
C0: "Panser"
C2: Pauline
C6: Donkey Kong Jr.; does nothing
C8: Big-eared creature that charges at Mario when his back is turned
CA: Donkey Kong Jr.; throws poison mushrooms
CC: Donkey Kong; throws barrels that can be kicked and picked up (1-8, 2-12, 3-8, 6-8, 7-12)

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Don't get your hopes up. I still can't figure out how to make a level that doesn't look like a n00b made it. As far as I can tell, it appears to use some sort of compression. If anyone feels like looking into this, go ahead. (and I mean please do so; I'm not so great with this kind of stuff)

Also, I forgot to mention that this is for the Donkey Kong (JU) (V1.0) [S][!].gb ROM.

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If I read one more person praising me or calling me awesome, I'll lose my mind!

Anyway, I found out that the levels simply use LZSS compression.

Here are some specifics on the variant of LZSS that GBDK uses:

In most cases, right after the 7 bytes that make up the header, you should see a number that isn't 00. When you reverse the order of the bits, they will show you whether the next few bytes are compressed or not.

Example from Stage 1-1:

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144D2: 00 07 0C 96 00 00 00 79

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Here, we see 79, which is 01111001 in binary. Reverse the bits and you end up with 10011110. 1 means the byte is uncompressed, while 00 means the next two bytes are compressed. Let's go back to our example:

---

144D9: 79 FF 01 0F 01 0A CD DF E0 D4 16 0F

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(I italicized the 0 bits and boldfaced the 1 bits to make things easier to see)

Bits set to 1 are nothing special. What you see is what you get. However, bits set to 0 are a little trickier...

What you need to remember is that the first byte is always the relative location of the tile(s) to duplicate, and the second byte is the length plus 3. For example, 01 0F would start at the tile right before these bytes (which in this instance is blank tile FF), and duplicate it 18 times.

If you're still confused, see Nemesis' document at RHDN for more information on LZSS compression.

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