Hi, thanks, I'm happy that you like this game so much.
About the attack animation bug, do you know a way to replicate this bug? Or do you have a screenshot or video to show when it happens specifically? Also, are you playing on the v2.0.1 version? Because the v2.0 had some debugging codes that I forgot to delete and some of them could trigger the attack animation, so this could be the reason of this bug.
Also, the green soul attacks are supposed to be hard and most of them tricky, though I'm not sure if there is much I can do about this, as this fight is one of the hardest in undertale, so I don't think that I can make the spears easy do block, and at the same time, I can't make the shield faster in most attacks, because then the player could just keep it spinning forever and no spear would be able to make it through.
Though, the next update will give the player the choice to not only customize the inventory, but also the weapon, which could make it easier to win against Undyne, as you could deal more damage, thus making the fight shorter and easier (but it will take a while, as the colored sprites are still far from finished and also because there will be new sprites and new animations, with a few new attacks also).
And don't worry, I like getting feedbacks!
Viewing post in Undyne the Undying fight remake comments
Attack animation bug was in both 2.0 and 2.0.1 it triggers mostly when you press x and z butons to skip intro, but i have no idea what causes slashing sprite to disappear randomly. Also when it comes to Undyne i think she's far more powerful and emotional than tricky. It is the hardest fight by far because of attacks being fully random and only following their pattern, but with high variety. Most fan fights made like a movie with fixated scenario, so you can wear blindfold and win it because you learned all the moves, but not this one, that fight each time a bit different
I tried spamming x and z as fast as I can, but I can't reproduce this bug, does it happen in the middle of the intro, while Undyne is talking? Unless you are talking about the attack animation that Undyne does at the end of the intro? In that case, it's not a bug, it's scripted, as Undyne's first attack will always be with the green soul mode, and you start with the red soul, so when the fight starts she has to turn you green.
Also, yeah, I agree with what you said, though she tries to trick the player with her attacks in the main game too by using spears with different speed and most of all the yellow spears. Though she still fights fair, trying to trick the opponent with a fake attack so that they block in the wrong direction isn't uncommon or unfair.
About the random attacks, I understand why most fangames use a fixed scenario, as you reset the time, so it's like nothing has ever happened and they do the same attacks, though I think that different things could make the battle different, like being in a different position or doing something different from the previous fight would make Undyne consider using another type of attack instead of the one she used previously, so I decided to give her random attacks(which will be much more random and pattern-less in the next update).