Fluidy (1967) by Andrzej Kondratiuk.
I came across this wonderful little experimental animated short film by Polish writer/directer Andrzej Kondratiuk, and just thought it was pretty great.
As I don't speak any Polish I've had great problems in finding any information at all on Andrzej Kondratiuk or this film (please enlighten me if you can).
This is however how Fluidy, made in 1967, is described on imdb:
"Very simple and minimal Polish animation about, as much as I can tell, confrontation. And the uselessness of it.
The two only characters, drawn in plain lines over a dull green paper background face each other for no apparent reason.
They fire lines, colors and shapes from their eyes, each responding to the other's provocations.
In the end, they seem to loose this power, respectfully bow to each other and walk away in opposite directions.
[...]The contrast between the dull characters and background and their hectic, geometric and colorful 'eye-fire' is the visual side of it. But the conclusion of their pointless confrontation has an existential feel to it."