The WebGL AttachShader error that some players are reporting is a problem that can occur with computers using integrated graphics. However, there is a workaround.
Step 1
Right-click on the game in your Steam Library, and select properties.
Step 2
Select the Betas tab, and choose "integratedgraphicsmode"
Step 3
Allow the game to install the IG version, and you've done it!
Please note that features such as achievements will not function in integrated graphics mode.