Well this happens because the alpha has only 25-35% of the content of the final release, releasing thar preview version earlier helps to find bugs in that content so the final release has less bugs at the end, and I released 0.6 almost at the end of september so I didnt had much room to delay more.
Talking of which, I am not fond on shilling but if you guys like the game, it takes a lot of time and resources: buying some assets, sending the text to edit, and the guy who is helping with the walkthrough and to help spell check (he has a list of things i need to fix that i will for 0.7), please consider supporting, even $1 helps, and I do polls that help to define future scenes, events, etc. so please consider it! The game will always be free and I will always try to answer as many questions as I can, but the workload is increasing a lot and new equipment among other things would help (I dont have an amazing PC and my wacom 3 has like 8 years) to speed up things! Thank you in advance!