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crimsonland.exe has several behaviors that look like genuine bugs. The rewrite fixes these by default, but they can be re-enabled with --preserve-bugs for parity testing.
Usage
Bug List
1. Bonus Drop Suppression: amount == weapon_id
Native behavior:
In bonus_try_spawn_on_kill, after spawning a bonus, the exe clears the spawned entry if bonus.amount == player1.weapon_id regardless of bonus type.
Why it’s a bug:
For non-weapon bonuses, amount is metadata (default amount) in a different integer domain than weapon IDs. This creates accidental “hard bans” where certain bonuses never drop while holding specific weapons.
Examples:
- Reflex Boost (
amount=3) while holding Shotgun (weapon_id=3) - Fire Bullets (
amount=4) while holding Sawed-off Shotgun (weapon_id=4) - Freeze (
amount=5) while holding Submachine Gun (weapon_id=5) - Shield (
amount=7) while holding Mean Minigun (weapon_id=7) - Speed (
amount=8) while holding Flamethrower (weapon_id=8)
Weapon bonus drops that match a currently carried weapon ID.
2. Greater Regeneration Has No Runtime Effect
Native behavior:perk_id_greater_regeneration is defined and unlockable, but no gameplay tick logic reads it. Only perk_id_regeneration is checked in perks_update_effects.
Why it’s a bug:
The in-game description says Greater Regeneration should replenish health “faster than ever”. It has a prerequisite (Regeneration), clearly intending an upgrade path.
Rewrite fix:
Greater Regeneration upgrades Regeneration heal ticks from +dt to +2*dt (same timing, double healing).
3. Bandage Applies a Health Multiplier
Native behavior:perk_apply computes roll = (crt_rand() % 50) + 1, then multiplies each alive player’s health by roll, clamped to 100.
Why it’s a bug:
The perk text says “restores up to 50% health”. A ×1..×50 multiplier is wildly different from a bounded heal and jumps from low health to full almost every time.
Rewrite fix:
Heal each alive player by +1..+50 HP (additive), clamped to 100.
4. Player-Facing Text Typos
Native behavior: User-facing strings include spelling/grammar mistakes in both gameplay data tables and UI copy. Evidence:analysis/ghidra/raw/crimsonland.exe_strings.txt
Rewrite fix:
Display corrected text by default. Examples:
Full text fix list
Full text fix list
| Area | Native Text | Fixed Text |
|---|---|---|
| Perk name | Fire Caugh | Fire Cough |
| Weapon name | Plague Sphreader Gun | Plague Spreader Gun |
| Weapon name | Lighting Rifle | Lightning Rifle |
| Weapon name | Fire bullets | Fire Bullets |
| Perk description (Anxious Loader) | waiting your gun to be reloaded | waiting for your gun to be reloaded |
| Perk description (Dodger) | attacks you you have a chance | attacks you, you have a chance |
| Perk description (Ninja) | have really hard time | have a really hard time |
| Perk description (Living Fortress) | It comes a time ... Being living fortress ... You do the more damage ... | There comes a time ... Being a living fortress ... You do more damage ... |
| Bonus description (Weapon Power Up) | Your firerate and load time increase | Your fire rate and load time increase |
| Bonus description (Fire Bullets) | For few seconds | For a few seconds |
| End note | the levels but the battle | the levels, but the battle |
| Quest failed | Persistence will be rewared. | Persistence will be rewarded. |
| Tutorial hint | Picking it you gets a new weapon. | Picking it up gives you a new weapon. |
| Tutorial hint | exposion | explosion |
| Weapon database | wepno #<id> | weapon #<id> |
| Weapon database | Firerate | Fire rate |
| Perk database | perkno #<id> | perk #<id> |
| Quest results | State your name trooper! | State your name, trooper! |
| Game over tooltip | The % of shot bullets hit | The % of bullets that hit |
| Statistics | played for 1 hours 1 minutes | played for 1 hour 1 minute |
5. Stationary Reloader Empty-Reload Loop
Native behavior:player_update preloads ammo when reload_timer - frame_dt < 0 (unscaled frame_dt), then later decrements reload_timer using reload_scale * frame_dt (with reload_scale = 3 when stationary).
When Stationary Reloader is active, reload_timer can underflow in a single tick even though the preload check was still non-negative, causing ammo to never refill.
Rewrite fix:
Use the scaled reload decrement for the preload check, so ammo is always refilled when Stationary Reloader causes same-tick completion.
6. Weapon-Drop Proximity Checks Player 1 Only
Native behavior: Inbonus_try_spawn_on_kill, when the spawned bonus is Weapon, the 56-unit proximity check uses only player1.pos. In co-op, a weapon drop near only player 2 does not convert to a 100-point bonus.
Rewrite fix:
Convert Weapon drops to 100-point bonuses when spawning within 56 units of any player.
7-17. Co-op Asymmetry Bugs
The original has 11 bugs where co-op behavior reads player-1-only state:7. Regeneration applies to player 1 only
7. Regeneration applies to player 1 only
perks_update_effects checks Regeneration via player-1-owned perk state, and heals only player1.health (repeated player_count times, over-healing player 1).Fix: Heal each alive player by +dt (or +2*dt with Greater Regeneration).8. Co-op heart pulse inherits player 1 low-health state
8. Co-op heart pulse inherits player 1 low-health state
In multiplayer HUD render, player 1 pulse speed (2.0 or 5.0) is reused for later heart icons. If player 1 is below 30 HP, player 2’s heart pulses at “low health” speed even when player 2 is healthy.Fix: Pulse speed is computed per player from that player’s own health.
9. Co-op damage/death SFX guard reads player 1 health
9. Co-op damage/death SFX guard reads player 1 health
In
player_take_damage, the “was alive before this hit” guard is computed from player1.health even when damage is applied to player 2. In co-op, if player 1 is dead, player 2 damage can skip SFX.Fix: Compute pre-hit alive guard from the target player’s own health.10. Jinxed excludes slot 383
10. Jinxed excludes slot 383
Jinxed chooses a random creature slot with
rand % 0x17f (383). The creature pool has 0x180 (384) entries, so index 383 is never picked.Fix: Use full 0x180 range for Jinxed random kills.11. Cursor-target perks read player 1 aim only
11. Cursor-target perks read player 1 aim only
Doctor targeting, Pyrokinetic hit lookup, and Evil Eyes all source aim from
player_state_table.aim_x/aim_y (player 1) regardless of which player is alive/aiming.Fix: Evaluate cursor-target perks per alive player.12. Jinxed self-damage always hits player 1
12. Jinxed self-damage always hits player 1
In the Jinxed “accident” branch, the 5 HP penalty applies to
player_state_table.health directly (player 1 only).Fix: Apply accident to a random alive player.13. Fire Bullets globally coupled in co-op
13. Fire Bullets globally coupled in co-op
projectile_spawn checks whether player 1 or player 2 has active Fire Bullets timer, but conversion is not owner-aware. One player’s timer converts the other player’s projectiles.Fix: Fire Bullets conversion is owner-aware.14. Pyromaniac offer gating checks player 1 weapon only
14. Pyromaniac offer gating checks player 1 weapon only
In
perks_generate_choices, Pyromaniac offer gate checks player_state_table.weapon_id == 8 (Flamethrower). In co-op, player 2 carrying Flamethrower doesn’t unlock Pyromaniac unless player 1 also has it.Fix: Allow Pyromaniac when any alive player has Flamethrower.15. Joystick POV aim reads player 1 POV only
15. Joystick POV aim reads player 1 POV only
input_aim_pov_left_active / input_aim_pov_right_active read POV input from joystick slot 0 only. In co-op, player 2 joystick aim can ignore player 2 POV input.Fix: Read POV input from current player’s input slot.16. Pistol no-magnet fallback gate checks player 1 only
16. Pistol no-magnet fallback gate checks player 1 only
When base 1-in-9 spawn roll fails, the extra pistol fallback (
rand % 5 == 1) is gated by player 1 holding Pistol. In co-op, player 2 holding Pistol doesn’t enable fallback unless player 1 also has Pistol.Fix: Allow pistol fallback when any player holds Pistol.17. Mini-Rocket Swarmers spread collapse
17. Mini-Rocket Swarmers spread collapse
player_fire_weapon sets per-rocket spread step to ammo * 1.0471976 (ammo * pi/3), then spawns ammo rockets at angle += step. Because heading is periodic (2*pi), some clip sizes alias to repeated directions. Example: with clip size 6, all six rockets get the same heading.Fix: Even, aim-centered cone spread so each rocket gets distinct heading.Impact on Parity Testing
For differential testing against original exe captures:Bug Detection in Source
These bugs were identified through:- Static analysis — Reading decompiled code and noticing asymmetry
- Runtime evidence — Frida captures showing unexpected behavior
- Parity divergence — Differential testing revealed mismatches
- Intent analysis — Comparing implementation vs in-game descriptions
Next Steps
Parity Status
Current verification state
Float32 Policy
Float precision policy
Rewrite Overview
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Source Code
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