No, my analogy holds up. It is entirely reasonable for people to judge a product as it stands at the time of its commercial release. I would actually agree with the OP about waiting until a game was complete if it was being produced by a hobbyist who was asking for feedback to improve their dev skills. But that is not the case here. Your title is Euphoria Studio and you have links to your patreon on the front page and in the game. That makes this a commercial product and we judge commercial products differently. Calling it a donation doesn't change the fact that there is a product/money exchange going on. Which is fine, I'm not against making money on a good product. But don't expect the hobbyist kid-glove treatment when you're shaking a tincup at your audience.
But let's consider your point about serialization. My analogy was to contrast against an entirely finished product because the OP was saying we should wait until the "serial" is entirely done until we judge it as a whole. But that's wrong. It is fine for people to judge a serial by the episodes that have been released. It is the job of those first few episodes to set the audience's expectations for what the rest of the serial is going to be like. You only get one chance to make a first impression, as they say. And all the responsibility for that impression sits with the creator. They don't get to say "here is my work, which I'm going to release piecemeal, and for which I would like to be paid beginning now and all throughout the release cycle, but please don't judge its quality until the last chapter is out". I'm sorry, but that is not a reasonable expectation to have.
As I said the option is there for devs to wait until they have a finished and polished product for release. Nobody is stopping any dev from doing that. If a dev chooses to release their game in bits then the audience is entirely justified in judging those bits on their own merits. It is the dev's responsibility to ensure that the product they are asking money for is good now. Not maybe sometime in the future, assuming it ever gets finished (unlike the thousand other abandoned projects on this site). Here and now as it stands. There are other games here that release quality episodes from the get-go. And they manage to do it without blatantly copying characters and setting from a much more popular and succesful game. Which is something we can't just gloss over. Because if this was just a hobby project that would be one thing. But you're asking for money while ripping-off one of the biggest games in the scene. And it is only right for reviews to point this out to your potential audience. Reviews don't harm the audience - they protect them from bad games. You made the choice to copy those characters. You made the choice to release the game in bits. You are solely responsibility for the quality of your game. The negative reviews are not unwarranted. They are a reflection of the product you have released and want to be paid for. And that product is bad.