I am somewhere between underwhelmed and whelmed.
Same...
god damn those full feats are baaaad.
Especially the "1st level" ones. some half feats are passable. some are good. might consider them at some level... some might even on 4th.
In no special order:
Scions: from one passable to good to most that are terrible:
of Air: a very good cantrip and useful ability few times per day. This would be a good half feat, but it is not.
Fey touched can get me Silvery barbs and misty step, both once per day and +1 to any mental stat to boot.
but still for this lot, it's one is of the better
of Earth: flavor cantrip, worse out of the three that we have in game, and wow, as a Bonus action give one creature cover bonus for one round?? why this does not stay until used again or for 24hrs or permanent until someone uses a shovel to get rid of it?
This is beyond bad.
of Fire: utility cantrip, not the best, but can be used creatively, and shite cantrip in addition. How is this a feat?
this is not worth a half feat. even if you can use it as a bonus action few times a day. what you are going to cast as an Action, this cantrip again. Better take Dash to run from shame for taking this feat.
of Water; flavor cantrip, middle of the three in game and stronger variant of Telekinetic feat with smaller range. But wait, there is more... this is not unlimited per day. And it does not removes components from casting Thaumaturgy, and it's not a half feat. What a joke!
of Outer Planes: utility or damaging cantrip, so something new at least. and resistance to damage that does not come that often. Better take guidance. Again as a half feat this could be passable. current 1/5. next!
Rune carver apprentice:
A utility spell that wizard has it as ritual at demand, you get it once per day. Yay!
and limited choice of 1st level spell to know and cast free once per day. Good half feat. Oh wait, it's a full feat.
Can I buy Magic initiate please?
Strike of the Giants:
I wont go into separate options, I think that they are equally (not)good.
At 1st, I missed that prof bonus per day is typed on the other page, and I was, wow, this feat is great. Did they really made an excellent feat, maybe too powerful, but hey, it's a playtest... but no, it's limited for few times per day.
Maybe if it worked as paladin's smites so you can decide after you hit, it would be worth it. With bonus action and mandatory effect on 1st attack, it's a bit weak, but probably strongest of 1st level full feats.
Now we go to the 4th level feats and most are half-feats. They might be learning something...
but 1st, full feats:
Cartomancer:
Now this IS promising. Nothing great, but there is some utility to get here for roleplay(a plus), some laughable damage boost, and chance to have some good spell on Bonus action so you can combine it with Dodge, Dash or Hide if need arises. A solid one. Maybe if damage boost would scale with prof bonus, like prof bonus×d4 it would be a good feat.
Planar wanderer:
full feat, after long rest pick one out of 3 resistances. Could come in handy. Portal cracker DC is too much. Portal sense range is too little.
This would be a good half feat.
Agent of Order:
a half feat. Good start.
gives few times per day restraint. But, why limit to 60ft. Everyone hates Elves and their longbows? But as it can be used with any damage effect, it is good versatility. Last only one round, so nothing to write home about. Still, as a half-feat, it's a contender for 4th level ASI. DC will probably be based of your highest score.
Righteous heritor.
preventing damage at a scalable rate, and not just for yourself as an reaction when you need it is a fine half feat to invest.
maybe if the die is d12, we do not see a lot of it.
Baleful Scion:
half-feat.
few times per day extra damage, get healed by that extra amount. Barbarian would like this feat the best. It can be triggered after hit, so it might be worth waiting for crit. Extra boost with paladin's smite. No complaint for this one.
Cohort of chaos.
I hate this random effects.
For rolling 1 or 20, it's cool that it is random, but for Bonus action, you should pick or at least roll twice on d4, and maybe get a pick if both d4's get the same number. Not great.
Ember of a fire giant.
this is mostly good, but a save should not reduce damage. At 4th level 1d8+2 is baad. Blinding is a good effect. Resistance to top it of. This is contender for a pick.
Fury of the frost giant:
again resistance with a half feat. Good.
Frigid retaliation. Range should be 60ft at least. Otherwise good effect for reaction.
Guile of the Shadar-kai...err...Cloud giant
reflavored shadar-kai racial. But a good rework, I like the more proactive effect with racial, but this is also good if you get jumped on.
No resistance here, but it's a teleport.
Keenness of a stone giant.
half feat with darkvision. Good.
And a limited improved magic stone. Mostly for darkvision, but stone is nice addon.
Outlands envoy:
half feat with misty step and utility 3rd level spell?
Might rather have Silvery barbs, but hey who wouldn't. Utility is excellent when needed. Good choice.
Soul of the storm giant:
again nice effect added to a half feat. Lightning or thunder resistance would be a nice addition, but it's OK.
So in the words of Krusk the barbarian:
HALF FEAT, GOOD!!
FULL FEAT, BAD!!