Lode Runner
Optimized port with original 23Hz engine & full OPL2 FM synthesis
Mission Overview & Story
An optimized port of the classic arcade platformer Lode Runner to the Picocomputer 6502 hardware platform. This port features the original 23Hz engine logic paired with smooth 60Hz visual interpolations, authentic retro graphics, and full Yamaha OPL2 FM synthesis audio integration.
Gameplay & Objectives
Navigate multi-story brick mazes, climb ladders, and swing across hand-to-hand ropes to collect every chest of gold on the screen. Outmaneuver chasing robotic guards by digging holes to the left or right to trap them. Trapped guards drop any gold they are carrying and allow you to safely walk over their heads. Once all gold is collected, escape ladders appear leading to the next stage.
OPL2 Audio Integration
- Background music (BGM) playback on the title screen utilizing raw YM3812 registers from
LODERUN.BIN. - Sound effects (SFX) routed to channels 5, 6, 7, and 8 for digging, falling, guard trapping, gold acquisition, dying, and level completion.
- Active voice management preventing hanging notes during game pauses, deaths, or level transitions.
Quality-of-Life Safeguard: Stuck Guards with Gold
Automatically handles gold held by guards trapped in permanent pits. If a guard carrying gold remains stuck in the same tile for 10 seconds, the safeguard removes/destroys the gold rather than depositing it onto the playfield (preventing situations where players could get caught trying to retrieve it). The level's win condition adjusts dynamically, triggering the hidden exit ladders if no other gold remains.
Controls Reference
Keyboard Controls
| Action | Key |
|---|---|
| Move Up / Climb Ladder | ↑ Up Arrow |
| Move Down / Fall | ↓ Down Arrow |
| Move Left / Right | ← → Left / Right Arrow |
| Dig Left | Z |
| Dig Right | X |
| Pause / Resume / Start | P, Esc, or Enter |
Gamepad Controls
| Action | Button / Input |
|---|---|
| Movement & Climbing | D-Pad or Left Analog Stick |
| Dig Left | X Button (GP_BTN_X) |
| Dig Right | A Button (GP_BTN_A) |
| Pause / Start | Start Button (GP_BTN_START) |
| Restart Level | Select Button (GP_BTN_SELECT, costs 1 life) |
Scoring & Multipliers
| Event / Target | Points | Effect / Notes |
|---|---|---|
| Gold Chest Collected | 100 pts | Required for exit ladder |
| Guard Trapped in Pit | 75 pts | Temporary immobilization |
| Guard Destroyed by Infill | 75 pts | Respawns at top of screen |
| Stage Clear | 1,500 pts | Unlocks next stage |
Pro Strategies & Survival Tips
- Holes dig into brick only — solid bedrock cannot be dug.
- Trapped guards will crawl out of holes after a few seconds if the hole does not fill first.
- You can walk across the head of a trapped guard without taking damage.
Gallery & Artwork
