I've played step 1, 2 and 3 and am playing step 4 without any DLCs but I can say with absolute certainty that this game is BEAUTIFUL! Many things are connected with each other and the development of the relationship with Cove is excellent! I got scared when I heard the song and saw the credits at the end of step 3 but seeing there was step 4 cheered me up A LOT, this kind of games deserve to be very popular, really, a lot of effort was put into this game and it really payed off, the way Cove's personality changes depending on your decisions, the customization of your character, the form of affection you choose to have with Cove and your relationships with others, along with different issues, the hardships of growing up, lots of memorable moments and a great OST, made this game my personal favourite, I've played it for days, a few hours at a time, and I can tell you that I 've never played a game that not only entertained me, but also made me feel such emotions with such ease, I really hope this game becomes way more popular because it deserves the popularity.
Well, I think I made it pretty clear, I love the game, I wrote the whole Bible in a comment expressing my love for it and I wish you good luck finishing everything in this game and the next ones you make! I'll most likely comment when I finish step 4, I already got some spoilers from the internet, but it only makes me more curious about everything!