Suggestions in DONTFORGET
Can you put this time proper text for acting with the characters with the P-Action?? Like with Niko, he say with his p-action in froggit.
"Um... You are THE frog."
Or Ralsei says:
"Can we play to jump later if you want!"
Get it? 
Abillity to reset your SPARE/Kill count.
The same spot where the credits are in the Last Corridor you'll be able to reset your spare and kill count. Here's the catch
for example: your kill count has to be above your spare count exp:
100 kills < 30 spares
The implementation of Undertale Yellow both on the map and in Vessels, or bosses just like they did now in 2.7.9
It would be interesting to see Clover, Marlet and Starlo fight Ceroba in a 3 on 1
Dear developers, please make this attack a little easier. It is difficult for me and probably most beginners to dodge it. Thinking you understand why.
(It is especially difficult for pacifists)
you could add a warning system so that people that did something wrong would be warned(for example 3 time and then banned, that would make it easier for people that want to redeem themselves to enjoy this amazing game
this is just my personal opinion but I think it'd be better if you added a way for banned people to join online servers whether that would be together or just normal people that would make it more enjoyable for everybody
There's only 3 flowey expressions, why not add more?
It's been said before but there's still time, more expressive animated sprites hell just make em move a bit instead of being still, oh and maybe make them colored, or pull a Tsunderswap and just give em flavor
I dont know if this is good or not but i had an idea for 2.8.0, with seeing the new genocide changes a thought came into mind what if once you eradicate an area you get like an alt costume, this simply being like a shadow over the eyes or something.
I'll be brief, gold/yellow color and sound for critical attacks from weapons with more than one reticle.
Like the example you will see below: