A Brand New Day is a long mod where Monika doesn't kill the other girls and MC, who is starting to remember his past lives (similar to The Good Ending), tries to save all the girls from their various problems. I would recommend the mod only to someone who has finished all the better DDLC mods and really wants to play more of them. Pros:
MC is a lot more of a real character in this mod. Instead of being a maximum blank slate with no traits, he's a lot more bold and outgoing in his attempts to woo the girls, and it's pretty funny at times.
The mod in general is really funny. Not only is the dialogue different in subtle and funny ways due to MC's new personality, but there are some great memes that had me laughing out loud.
Despite the above, it doesn't skimp on the serious plot. There's still a threatening opposition, and unsolved mysteries that seem promising (the game ends with a "to be continued" screen). (Update: it's been several months. I don't think it's ever going to be finished.)
I've tried to organize my criticisms in order of descending importance, but it was hard to decide:
The biggest one is how the mod treats MC like he only exists to make the girls happy and doesn't have any rights of his own. In particular, in the scene where he shares wine with everyone (see below), Sayori drinks his entire glass (in addition to her own) while he's reading the bottle and then Natsuki and Monika drink the rest of it before he can pour himself a refill (I know, the logistics of the scene were far from realistic). This would be scandalous even if it weren't after he's saved almost all of their lives at least once.
The intense statism of the scene where Yuri offers everyone wine at the club, but Monika says no, not because they don't want it, but because they're "underage", and she even commands MC to take the bottle and throw it away. Do the mod authors not realize how evil that is? Refusing to break the law is one thing, but stealing and destroying someone else's property? Thankfully, the mod sabotages its own messed up moral by having MC only pretend to throw the bottle away, and later get it out and share it when they all go to his house. He manages to convince Monika to allow it this time by arguing that since they've relived the events of the game so many times, their "real" age is probably around 21 or 22. Still, it's a big problem that no one ever called Monika out for trying to destroy Yuri's property (not even Yuri). What she did in that scene was downright evil.
When MC goes to fight Natsuki's dad, Sayori and Natsuki both should have been there to help him, but instead they leave him on his own, not only insinuating the idea that MC only exists to make them happy (see above), but also exemplifying the sexist trope that girls are no good for fighting. While it may be true that girls tend to have less physical strength than boys, it is by no means such a big gap that they shouldn't even bother helping.
MC was wrong to lie to his friends (about the meta-canon) for the majority of the mod. While he does eventually reveal the truth, it's only after they start to remember it on their own, so the mod still sends the message that it's okay to lie to one's friends if you think the truth would hurt them or that they don't "need to know". And even then he leaves out the part that villifies Monika. While that's a little more justifiable since there's a risk that the other girls wouldn't forgive Monika and might try to take revenge, it's still wrong.
The portrayal of Sayori was inaccurate and insulting. In the base game her depression stems from a lack of self-worth and feeling that she is a burden on MC and her other friends, but in this mod she doesn't seem to have any problem with making herself more of a burden, like when she steals his wine (see above), or is the second person to order an absurd amount of food when MC takes the girls out for dessert and pays for all of it.
The scene where MC finds Yuri cutting in the hallway and she punches him in the face and knocks him out is a little sexist. Not only because this was unprovoked physical assault (somewhat defensible as the "reflex punch" comedy trope and with MC's new personality it's believable that he wasn't mad), but also the thought that she actually knocks him out with just one punch. I'm pretty sure that's nearly impossible to do in real life.
Both times MC stops Yuri's suicide, he takes her knife - which makes sense - but then he never gives either of them back. Granted, Yuri never asks about it, but still, the implication that he plans to actually steal her property is disturbing. It's not like he could actually stop her from killing herself just by confiscating all of her knives, anyway.
There's one last thing I need to mention. There's a release of "A Brand New Day day 12" around somewhere, but it's not a serious continuation of the story. It is at best a complete waste of your time and at worst a seriously scarring experience. Basically (I won't even spoiler it) the girls kidnap and horrifically torture MC to death, and then it's revealed that "got you - it's april fool's day". I actually couldn't keep going at a point and decompiled the scripts to see how long it went on.