The Four Patterns That Keep a Browser Game Shippable
Every browser game starts the same way. A canvas, a sprite, a requestAnimationFrame loop, and something moving on screen within an hour. The difference between the projects that ship and the ones that quietly die six weeks later is almost never the graphics or the idea. It is the shape of the code underneath.
Games stress code in ways ordinary web apps do not. A form validates a field and sends a request. A game updates hundreds of moving objects sixty times a second, renders them, reads input, runs physics, plays audio and checks win conditions, all inside a budget of about sixteen milliseconds. Everything is connected and everything is on a clock. That is why games grew their own catalog of patterns over four decades, and why four of them do most of the work.
Why the Web Punishes Sloppy Structure
JavaScript is single-threaded by default, so anything you do on the main thread competes directly with rendering. The garbage collector can pause the game for several milliseconds at a moment of its own choosing, which turns a smooth sixty frames per second into a visible hitch. And browsers run on everything from a high-end desktop to a three-year-old budget phone, a hundredfold spread in hardware for one codebase.
There is no compiler standing between you and a tangle of cross-references either. When the player object calls straight into the audio manager, the particle system, the score display and the network layer, every change ripples outward in ways nothing warns you about.
The Loop and the Fixed Timestep
The loop is the center of the program. It reads input, advances the simulation, draws the result, and repeats. On the web that loop is driven by requestAnimationFrame, which fires at whatever rate the display runs.
The trap is advancing the simulation by whatever time elapsed since the last frame. Do that and your player moves at different speeds on a 60Hz laptop and a 144Hz monitor, and a single long frame lets a fast object pass straight through a wall because the collision check never saw it inside.
The fix is a fixed timestep. Accumulate elapsed time, step the simulation in fixed slices of roughly sixteen milliseconds while the accumulator allows, and render the latest state, interpolating if you want it perfectly smooth. Physics becomes deterministic and identical across devices, which also makes bugs reproducible instead of a matter of luck.
Composition Instead of Deep Inheritance
The second pattern shows up the moment content grows. You write an Enemy class. Then one enemy shoots, one follows the player, one does both, one is invulnerable while charging. With inheritance you get a class tree nobody can hold in their head, and a base class with forty methods that exist only because one subclass needed them.
Composition inverts it. An entity is an identity plus a set of components: position, sprite, health, weapon, AI behavior. A new enemy variant is a different set of components, often a different line of data rather than any new code at all. An entity component system takes it further, storing components in contiguous arrays and running systems over them, which is friendlier to the cache and much friendlier to the person adding a feature at midnight.
Keeping the Hot Path Allocation Free
The stutter players feel is usually not drawing. It is the garbage collector cleaning up thousands of short-lived objects that the game created and discarded, frame after frame. Every new vector, every particle, every bullet allocated on the fly adds to the pile.
Object pooling fixes it. Allocate the bullets, particles and enemies once, keep them in a pool, and reuse them instead of creating and discarding. A well-behaved game allocates almost nothing during play. The same discipline covers event objects and temporary vectors, which are the two that hide the longest.
The fourth pattern comes free with the third: decoupling through events and state machines. When systems talk through an event bus instead of direct references, adding a pickup that plays a sound and updates the heads-up display touches one file instead of five.
What to Do on Day One
None of these are hard to adopt at the start, and all of them are painful to retrofit in month three. Write the loop with an accumulator before you have anything to simulate. Give your first entity a component list even though it has two components. Pool the first thing you spawn in bulk. Route your first cross-system message through an event.
That is maybe an extra hour on day one, and it is the hour that decides whether month six is still fun.