Echo

Inspiration

I wanted to flip the idea of glitches on its head. In most games, glitches are accidents — bugs you report, things you avoid. What if the entire game was designed around exploiting them? What if glitches were the only way to win?

I also wanted to tell a story like Sword Art Online — a player trapped inside a virtual world, a companion who turns out to have a secret, and a final boss who created the prison. Combining that emotional arc with glitch-as-mechanic felt like something genuinely new for a hackathon game.

What it does

RUN.EXE is a 10-level pixel platformer where you play as RUNNER, a speedrunner who gets trapped inside a game by a developer called DEV. Each level unlocks a new sword with a unique glitch power tied to it — wall clipping, freezing time, corrupting enemies, phasing, warping, cloning, crashing, rewinding, overloading, and finally deleting reality itself. Your primary weapon swings on Z, and critically, swinging also deflects enemy projectiles back at their source — turning the game's danger into your offense.

Your companion ECHO floats beside you the whole way, cheering you on, warning you of danger, reacting to hits and boss phases. By the midpoint of the game you learn she was built by DEV to deliver you to him. She chooses you instead. The final fight is the two of you against her creator.

Three boss encounters punctuate the run — two mid-game guardians and a three-phase final battle with DEV himself.

How we built it

Everything is vanilla HTML5 Canvas and JavaScript — no game engine, no external libraries, a single .html file that runs instantly in any browser. That includes a custom physics engine for gravity and platform collision, fake-3D pixel art built from layered shaded rectangles to give characters depth without needing a 3D renderer, a sword-swing combat system with per-weapon arc shapes and timing, and the deflect mechanic itself — detecting projectiles entering a timed hitbox during the swing and reflecting them back with damage.

ECHO's behavior is driven by dozens of contextual dialogue lines tied to game events: getting hit, boss phase transitions, level completions, and the story's emotional beats. She has her own lightweight movement physics so she actually floats and reacts in space rather than just sitting static next to the player.

Challenges we ran into

Balancing difficulty was the hardest part. Early boss fights were nearly unbeatable because melee-only combat with low player HP and frequent enemy fire didn't leave room to learn the patterns. We had to iterate on boss HP, projectile speed, and damage numbers multiple times to make the fights feel fair instead of punishing.

The deflect system itself took several passes — getting the timing window and hitbox size right so it felt responsive rather than either too forgiving or impossible to land. We also hit a tricky bug where the deflect logic existed in the code but was never actually being called during gameplay, so shots simply weren't deflectable until we tracked that down.

Accomplishments that we're proud of

Building a complete 10-level platformer with bosses, a full story arc, and an original combat system in a single dependency-free HTML file. We're especially proud of the deflect mechanic — it turns enemy attacks into a resource instead of just a threat, which made the boss fights feel genuinely strategic rather than just damage races. The fake-3D pixel art also punches above what we expected from layered Canvas rectangles alone.

What we learned

Glitches as a design language are more flexible than expected — clipping, freezing, and rewinding all read as "broken" but each demands a completely different play pattern. We also learned that a companion character with even a small amount of reactive dialogue makes a simple pixel game feel dramatically more alive, and that balancing a melee-only combat system requires much tighter HP and timing numbers than a ranged shooter would.

What's next for Echo

A full level editor so players can design their own corrupted stages, more glitch types like gravity inversion, and a proper ending sequence where ECHO gets her own existence outside the game world — plus exploring her perspective as a playable character in a future mode.

Built With

• canvasapi
• css
• html5
• javascript