elliottash/megaman-maker-levels

Mega Man Maker level corpus

A unified corpus of 179,166 user-authored Mega Man Maker levels for training MarioGPT-style text-to-level models, procedural-content generation research, and platformer-level analysis.

Each row carries:

• A MarioGPT-style ASCII tile grid (level_ascii) — list[str], one string per row of the level — ready to feed directly into a GPT2 / BPE tokenizer with no further preprocessing.
• A natural-language text_prompt automatically composed from the level's structural features ("underwater, many enemies, few pickups, has boss, medium, low elevation, difficulty expert") — modeled after MarioGPT's prompt vocabulary.
• The full parsed intermediate representation (IR) as gzipped JSON (ir_json_gz).
• The original raw .mmlv bytes (mmlv_bytes) when retained.
• The full webmeka.io engagement metadata — likes, dislikes, downloads, crowd-sourced difficulty, boss enum, author, creation timestamp.
• A webmeka_url link back to the level's webmeka.io page.

Quickstart

from datasets import load_dataset

ds = load_dataset("<namespace>/<repo>", "default", split="train", streaming=True)
ex = next(iter(ds))
print(ex["text_prompt"])
#> underwater, some enemies, few pickups, has boss, medium, medium elevation
print("\n".join(ex["level_ascii"][:14]))

Train MarioGPT-style with "\n".join(level_ascii) as the GPT2 input and text_prompt as the conditioning prompt.

Configs / subsets

Config	Rows	Description
default	179,166	Every parseable level.
mmm_liked	54,304	likes>=10 AND quality_score>=0.5 — training-grade.
mmm_boss	178,517	Levels that ship a Robot Master boss.
mariogpt_compat	22,084	ASCII grid ≤17 rows tall and ≤256 cols wide.

ds = load_dataset("<namespace>/<repo>", "mmm_liked", split="train")

ASCII legend (level_legend_version = "v1")

Glyph	Meaning
-	empty / passable
X	solid (ground / wall / breakable)
=	semisolid / one-way / jump-through
H	ladder
W	water / liquid zone
*	hazard (spike, lava surface)
?	item block (solid + collectible)
o	pickup / collectible
E	enemy
B	boss / controller anchor
G	goal / level exit
P	player spawn
g	gizmo (switch, spring, pipe, ...)
.	unknown / reserved

The mmm_decode.py helper that ships in this repo includes a Pillow-based ASCII-to-PNG renderer using the same palette.

Column schema

Column	dtype	Description
mmm_id	int64	Numeric Mega Man Maker level id (matches webmeka.io URL).
webmeka_url	string	https://webmeka.io/level/{mmm_id}.
ir_id	string	mmm_<mmm_id>; matches Meta.id in the parsed IR.
level_ascii	list	MarioGPT-style tile grid, one string per row.
level_legend_version	string	v1. Increments when the glyph table changes.
ascii_width	int64	Width of the ASCII grid in tiles.
ascii_height	int64	Height of the ASCII grid in tiles.
text_prompt	string	Comma-separated MarioGPT-style prompt.
theme	string	First useful source tag (platformer fallback).
elevation	string	low elevation / medium elevation / high elevation.
width_bucket	string	single-screen / short / medium / long / very long.
height_bucket	string	low ceiling / medium ceiling / tall.
enemy_count	int64	Count of E glyphs.
pickup_count	int64	Count of o + ? glyphs.
hazard_count	int64	Count of * glyphs.
gizmo_count	int64	Count of g glyphs.
ladder_count	int64	Count of H glyphs.
water_count	int64	Count of W glyphs.
boss_count	int64	Count of B glyphs (+1 if webmeka flagged a boss).
spawn_count	int64	Count of P glyphs.
goal_count	int64	Count of G glyphs.
has_ladders	bool	True when ladder_count > 0.
has_water	bool	True when water_count > 0.
has_boss	bool	True when boss is present (grid or webmeka).
glyph_counts	struct<string,int64>	Glyph histogram across the entire legend (0 for absent glyphs, so every row has the same key set).
webmeka_name	string	Level title as displayed on webmeka.io.
webmeka_author_id	int64	Webmeka author id.
webmeka_author_name	string	Webmeka author display name at scrape time.
webmeka_author_icon	int64	Author icon enum.
webmeka_created	string	ISO-8601 creation timestamp.
webmeka_boss	int64	Boss enemy enum from webmeka.
webmeka_likes	int64	Number of likes.
webmeka_dislikes	int64	Number of dislikes.
webmeka_downloads	int64	Number of downloads.
webmeka_difficulty_score	float64	Crowd-sourced difficulty in [0, 1].
webmeka_difficulty_label	string	Bucketed difficulty (Easy, Normal, Hard, Expert, Super Expert).
webmeka_tags	list	Webmeka tags (traditional, puzzle, boss, automatic, …).
name	string	Name as recorded inside the .mmlv.
author	string	Author as recorded inside the .mmlv.
difficulty_label	string	Same buckets as webmeka_difficulty_label; copied into the IR Meta.
ir_quality_score	float64	likes / (likes + dislikes).
width_tiles	int64	Level width in 16×16 tiles.
height_tiles	int64	Level height in 16×16 tiles.
tile_width_px	int64	Source tile width in px (always 16).
tile_height_px	int64	Source tile height in px (always 16).
tag_list	list	Tags carried inside the IR (megaman_maker, platformer).
ir_format_version	string	Parser format version (mmm_parser_v4_raw).
region_count	int64	Number of raw MMM regions (one per contiguous tileset block).
region_tileset_ids	list	Raw MMM tileset_id per region. Empty for levels parsed with mmm_parser_v2 (no region table); populated under mmm_parser_v4_raw. Use first_tileset as a v2-friendly fallback.
screen_count	int64	Number of webmeka screens stamped in extra.screens (nullable for legacy IR).
total_entities	int64	Entity count across all layers / regions.
first_tileset	string	Name of the first IR tileset (rough biome hint).
tile_layer_count	int64	Number of top-level tile layers.
tileset_count	int64	Number of distinct tilesets referenced.
ir_sha256	string	SHA-256 of the canonical-JSON IR bytes (for dedupe).
ir_json_gz	binary	gzipped UTF-8 JSON of the full IR Level.
mmlv_bytes	binary	Raw .mmlv file content (when retained).
mmlv_sha256	string	SHA-256 of the raw .mmlv bytes (for dedupe).
thumbnail_png	binary	Pre-rendered PNG of the ASCII grid (when --thumbnails was used).

Provenance & license

• Source content — user-authored Mega Man Maker levels hosted on webmeka.io. The .mmlv files contain ONLY symbolic ids (e.g. d=8 e=22 means "Robot Master id 22" — Bubble Man inside the Mega Man Maker engine) plus tile coordinates and screen settings. They contain no Capcom assets — no sprites, no music, no images — only integer references to assets the Mega Man Maker engine renders at play time.
• Metadata — webmeka_* columns mirror the public webmeka.io search API as observed on 2026-05-23.
• Parser — level_ascii, text_prompt, and ir_json_gz are derived by the open-source level-corpus pipeline (format version mmm_parser_v2).

The level layouts are user-authored, and this dataset is released under CC-BY-4.0 for research and PCGML use. "Mega Man" is a trademark of Capcom Co., Ltd.; this dataset is not affiliated with or endorsed by Capcom. If you are a level author and would like your levels removed, please open an issue on the dataset repo.

Quality filtering

The default config is unfiltered so consumers can apply their own quality bar. The included engagement columns make this easy:

ds = ds.filter(
    lambda x: x["webmeka_likes"] >= 10
    and x["webmeka_dislikes"] < x["webmeka_likes"]
    and x["webmeka_downloads"] >= 20
)

Or load the precomputed mmm_liked config directly.

Distributions (this build)

• Total rows: 179,166
• Rows carrying raw .mmlv: 179,166
• Rows carrying parsed IR: 179,166
• Rows carrying ASCII grid: 179,166
• Rows carrying thumbnail PNG: 179,166
• IR format version breakdown: mmm_parser_v2 (179,166)
• Difficulty buckets: Hard (42,844), Easy (33,050), Expert (32,389), Normal (32,136), Super Expert (16,714)
• Top themes: platformer (179,166)

Citation

If you use this corpus, please cite the level-corpus repository (which ships the .mmlv parser used to produce the IR + ASCII + text prompts) along with the webmeka.io community as the data source.