The horizontally opposed engine (aka flat N) is nothing new. More specifically I know it has been in Honda motorcycles since the 1970's. Cars and other devices likely too but I have no first hand knowledge of that.

Here they are giving it a new name and say they can reduce the amount of moving parts by 50%. There is no information on what "parts" they are removing which I would find to be the most interesting piece of information. The comparison of two and four strokes engines is also misleading.

After a quick dig: If you go to eco's website they specifically say this is a two stroke engine; the article linked has incorrect information.

They are reducing the amount of parts because they are using a two stroke instead of a four cycle.

It seems the only real cool part of this engine, to me, is that it is designed "modular," it should be more cost effective to add on additional cylinders instead of having multiple facilities dedicated to different configurations.

Flat configurations have been used in cars and motorcycles for decades.