This film depicts the construction and launching of two improvised hot-air balloons. There were actually three. The first was an utter failure, because they had utilized a cotton-based fabric that was porous and leaked air massively.
This event was first portrayed in Fuga nella notte (1982), an English-language Disney production starring John Hurt and Beau Bridges.
The film perhaps portrays life in the GDR in a slightly favourable light with almost everyone already owning cars, sewing machines, houses (not flats), digital watches, TVs etc - the reality being that for most people their was a shortage of assets like this. That said, by the 1980's the GDR government had made great strides in equalising the value of currency with their Western peers and escapees would be surprised at the relatively small differences versus what they had escaped for - other than having greater freedom and choice - potentially priceless.
Many of the cast members, including the two leads, were born in East Germany.
Thomas Kretschmann was born in East Germany himself, and escape the country when he was 19.
During his month long trek, he crossed 4 borders with nothing other than a passport and the equivalent of $100 in his possession, and he lost part of his finger to frostbite.