Frameworks & Libraries for Low-Spec Art

LÖVE is a small, well documented Lua framework with nearest-neighbour filtering and canvases that make pixel-perfect rendering easy.

Phaser is the most used JavaScript framework for 2D games in the browser. It covers sprites, tilemaps, physics, input, audio and scene management, has a very large body of examples and tutorials behind it, and runs anywhere a browser does.

raylib is a no-dependencies C library with bindings for dozens of languages, well suited to small low-resolution games.