This engine form has been around for ages, even though it may not have been properly developed before now. Back in the 1960s, car air conditioner compressors were built with this configuration. It isn't a difficult stretch of the imagination to transform it into an engine.

While I haven't looked at this particular engine in detail, it is probably built as a 2-cycle engine, although its form could be converted into 4-cycle with a little effort. All modern automobile engines are 4-cycle. Two-cycle was outlawed for selling by car and motorcycle companies in the U.S. back in the '70s because it was claimed to be too polluting.

Generally, a 2-cycle engine is much more powerful than a 4-cycle, size for size. However, fuel consumption is usually higher for a 2-cycle compared with the amount of power produced.