It is a general test to look into the game as a whole and identify any issues which should be adjusted before release. Late-game features are the least tested right now so having people who will try to complete the game is ideal.
From the volunteer's standpoint, we just want you to play normally and then answer some questions about how you felt while playing. We will watch your recording to understand behaviours such as where you explored first, how many times you attempted each boss fight, etc, as well as identify any bugs experienced. There will be a closed discord to discuss the game with other testers as well.
The game should work on Linux so it would be very useful to have someone playing in Lubuntu :)