About
1JETPACK.EXE is a browser-based (Web) remake of Jetpack that is currently listed as semi-complete. It includes a built-in level editor where players can place tiles and immediately playtest the level they're building.
Getting started
Move with the arrow keys, press Alt to jump or fly, hold Ctrl with the arrow keys to phase through red bricks, and press down to use teleports and switches. In the level editor, Enter shows or hides tiles, the arrow keys select a tile, and Space places it; press P to playtest the level and Backspace to return to editing.