Story/Invasions:
Story mode is pretty good even though the story becomes really weird and a complete fan service at one point. Invasions is weak, you cannot get a full vision of the map so at times you'll get completely lost and have no way to visualize where you are or where you want to go. The RPG element of invasions is basically non existent, you don't have to think about your build or stats to advance and items are completely unecessary.
Training mode:
It is the worst I have ever seen in a fighting game, there are very basic options such as restarting on corner with simple inputs not being present, there's no way to display selected moves on screen during your training (you could do that in MK11) and menus in general are very clunky, if you want to watch replays you have to go through every single menu you need to every time you want to watch another replay even if it is yours.
Online:
I have not explored much of the online so I'm not sure how good it is but at least the netcode seems to have improved. Matchmaking however seems to be pretty bad, I constantly find the same players to fight against and this is basically Day 1 experience so unless Crossplay gets implemented as it was promised it could be a very limited experience,
Overall I don't think MK1 is worth atm. It's too expensive and it feels rushed since some really basic features are missing. Removind Kameos and hiding them behind Grind walls also is something that makes this game hard to recommend.