I'm building a complete Space Invaders game in a single HTML file with a player ship, a 5x11 grid of aliens, movement mechanics, alien firing, destructible bunkers made from pixel blocks on an offscreen canvas, score tracking, lives, multiple levels, and game over/restart functionality.

Defining sprite graphics for three alien types (squid, crab, and octopus) as pixel art arrays with two animation frames each, then scaling them to fit consistently within the game.

Now I'm setting up the player sprite as a rocket-like shape, then planning the core game loop with delta time, fleet movement mechanics that accelerate as aliens are destroyed, particle explosions, and input handling for movement, shooting, pausing, and restarting.

I'm building out the full implementation with collision detection between player bullets and aliens, alien bullets hitting the player and bunkers, and bunker destruction. For the bunkers, I'm generating a procedural mask that creates an arch shape with rounded top corners and a notch cut into the bottom center, using a grid-based approach where each cell is either solid or empty based on its position.

Writing the game code... Implementing damage mechanics that remove cells within a radius of about 5 pixels from the impact point, with some randomization to make the destruction feel more natural.