The strategy aspect may not be for everyone. The game's short enough for multiple sessions, so I'm hoping that even players who are not that much into it will be able to gradually learn the game and do better in future attempts.
There are 9 endings and yes there's a gallery for after the first time you finish the game. The endings are not fully finished yet and aren't viewable in the gallery but they are tracked for future updates, so they'll become viewable for players who have collected them when that feature is added.
There are 4 endings for each companion and protagonist combination. After you go on 2 dates together the final quest will start, finish it before time runs out. Alternatively defeating the cauldron after getting all of the location clues is always available if you have missed your chance to get a companion ending.