I'm really enjoying nightwave, and I'm liking the difficulty of some of the challenges too. I just got my hundred day login, so I'm no veteran, but I'm not too new, and as such I appreciate that the challenges tend to be doable, or at least enough are that I don't need to worry, and generally the only reason I can't do them is cause I just need to "git gud" or get better mods.
However the most recent one "complete five sorties" really sucks. It entirely defeats what I thought was the purpose of Nightwave: that it allowed casual and weekend players to get the Alert rewards, without having to hope for the perfect time. This challenge however, requires at least five days of gaming (assuming the sortie is doable, which is less important but hey), which means it's really hard or impossible for some of us to complete. I have uni four days a week, so I can't do this purely due to time, which was the problem with the Alerts.
This has been my only real gripe so far. I disliked the Kuva survival, but I was probably just too underpowered.
The only other thing I would say is please increase the amount of Wolf Creds (or whatever the next ones will be), or add an alternative way to get them. As it stands, it takes two weeks minimum (I think) to get any wolf creds, which kinda sucks if you're only looking for the old Alert rewards.
That's my two cents. I am really enjoying it though, and I look forward to the upcoming challenges and seasons.