It dies with lots of WebGL errors here, so I only see a white page. So that's definitely not ASCII in my book. Would be more fun to have an actual text based output indeed.
This is an older Firefox, so this is probably all "normal", but also may be entirely unrelated to the actual cause for nothing showing up?
WebGL warning: drawArraysInstanced: Framebuffer not complete. (status: 0x8cd6) COLOR_ATTACHMENT0: Attachment has no width or height. ascii_clouds.astro_astro_type_script_index_0_lang.iEVYfoCC.js:274:3430
WebGL warning: drawArraysInstanced: Framebuffer must be complete. ascii_clouds.astro_astro_type_script_index_0_lang.iEVYfoCC.js:274:3430
WebGL warning: drawArraysInstanced: TEXTURE_2D at unit 0 is incomplete: The dimensions of `level_base` are not all positive. ascii_clouds.astro_astro_type_script_index_0_lang.iEVYfoCC.js:274:3980
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[repeat]
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WebGL: No further warnings will be reported for this WebGL context. (already reported 32 warnings) ascii_clouds.astro_astro_type_script_index_0_lang.iEVYfoCC.js:274:3430
