Since we have a growing list of features that have yet to be implemented into the game, I figured just for fun, since I am bored at the moment, why don't we just list them out. I have included when they were supposed to have been added according to the DMM timeline as well.
Note: I only went so far back, so if I am missing any important things, just let me know and I can add.
Note 2: We are listed as approximately 1 year, 2 months, and 9 days behind DMM.
Note 3: I will try to keep this updated, and when we get the feature I will cross it off with the day it was added.

List of Things that should have been added, but were not yet

• Gold Exchange Shop - Should have been added some time before 7/3/2018
• Danchou Tickets - 7/3/2018 but possibly earlier
• Aqua Shadow Missions - 7/10/2018
• Ability to buy Petals in Gold Exchange Shop - 8/7/2018
• Accept All Completed Quests at the same time - 09/18/2018
• Bond Crystal Exchange Girls - 10/18/2018
• Garden Medals Added (allows you to avoid spending gold) - 11/6/2018
• Ability to mix and match skins between character versions - 11/6/2018
• Permanent Revivals was supposed to start again - 11/15/2018
• Warehouse 2.0 - 12/4/2018
• Loading Screen Trivia (not very important but I kind of like it) - 12/11/2018
• Super Counter and Chance to Resist Death for all Defensive Knights - 12/18/2018
• The 40 Medal Danchou Ticket was added - 1/1/2019
• Solar Drive Revamp (You can now over charge solar drive to 300%) - 1/8/2019

Other Updates - Writing these as these do not really needed to be added unless you have the dates.

• We are missing over 100 Blooms (too many to count).
• We are behind on whaleship, campaign missions, and severely behind on concept missions.
• Quests Severely behind - We should have more stages to the main quests.
• Character Quests.... I ain't even going to go there.

Really impressive list Ampchan. Though I'm curious, : how did you get the dates for when we should have gotten these features? I've looked everywhere and couldn't find the date for when DMM got warehouse v2, so I'm surprised you got the dates for ALL these features.

Anyway, here's all the features I can think of that DMM has that we don't (However, I don't know when DMM had any of these implemented so I'm not sure if we should have them yet):
- Manyu Key Stages - These will likely be added soon though.
- Quest Completing Cumulatively - So you can clear one type of quest all in one go without needing to backtrack to the Quests page to claim rewards.
- Lvl 100 Manyu Forging - Can convert x3 Lvl20 Manyus into x1 Lvl100 Manyu.
- Ally Slots from early Campaign Missions - My Level 75 account on DMM has 59 slots and my Level 150 account on Nutaku has 37.
- Multiple Assistant Leaders - The Assistant Leader that's shown on your homescreen changes can be multiple girls of your choice.

The dates come from the patch notes that the developers on DMM put out. They make really good patch notes. I just started reading through them all. Dates determined by matching event counts.

Originally Posted by Ampchan

The dates come from the patch notes that the developers on DMM put out. They make really good patch notes. I just started reading through them all. Dates determined by matching event counts.

Ah that makes sense, I never bothered looking at them cuz they're in Japanese.

I agree, this is an excellent summary. I hope Nutaku picks up the pace in the future.

pastebin.com/Na7EUXEt

Sorry to shoehorn it here, but if it helps, I also had made a big list of DMM updates a while back. It's outdated and doesn't list exact dates, though, so the OP summary is better.

Does super counter count as a missing feature? Basically, if a unit counters and the defense shield activates, the counter should be more powerful. No idea when this was added to DMM. Also, there is the crit rework, which I believe makes it so that you can crit against enemies you have type advantage over. Again, no idea when DMM got this. Can try to look into it when I get home.

Originally Posted by unknown68

Does super counter count as a missing feature? Basically, if a unit counters and the defense shield activates, the counter should be more powerful. No idea when this was added to DMM. Also, there is the crit rework, which I believe makes it so that you can crit against enemies you have type advantage over. Again, no idea when DMM got this. Can try to look into it when I get home.

Super counter is mentioned above. And we already have the crit rework (I think). The problem is that when you get a type advantage crit, the number just doesn't even show up. You still deal the damage though.