I think we discussed that on slack/discord already.
No ECS provided by the engine, but some people talked about that stuff via chat, so not sure if someone will work on a ECS engine.
Regarding to shaders: Shaders on KorGE are usually applied via filters, and created using a DSL for that. Please, check this link: https://github.com/korlibs/korge/blob/16aac42d6cf0e4eed19e088e12b73282661cf0f4/korge/src/commonMain/kotlin/com/soywiz/korge/view/filter/WaveFilter.kt#L31-L40