The developers announced temporary free access to the full game: from October 8 at 11:00 CEST until October 12 at 10:00 CEST. The announcement also introduces a major update to Frozen Trail.
The trial period is convenient to use to test the connection, control and play together with friends. Temporary access does not mean a permanent license: after the end of the window, check the conditions in the store. The Frozen Trail description mentions new territory, enemies, equipment, and progression changes. If you're coming back after a break, first read the current character development information, then compare it to the old build. Start and end times are based on CEST, so please consider your time zone when scheduling your last session.