Dragon Incarnate - Version 0.1.8 by Agent Nova Win/Mac

After a rocky start, you and your companions will embark on a journey to discover the secrets of the dragons. The main story can be progressed through the main quest at your own pace. There are side quests, companion quests, mini-games, puzzles, and more to discover outside of the main quest.

Although a Visual Novel, there are sandbox elements and even some romance options. You can choose your character's gender (male/female/futa), and rename your character. Romance options are completely your choice. You can even complete companion quests without needing to romance them.

Everything is optional. Nothing can be missed. (Although you will need to advance the main quest to unlock access to new things.)