@Inconspicuosaurus (seriously man, that is just the most hilarious user name), The card is a bit weird. It works like Djinni of Zephyrs, but it also counts damage and Hero Powers. As we have seen from Djinni of Zephyrs, this effect can be pretty hard to utilize, and your card is even harder to make use of because of the shared damage. I would buff it's stats, give it some other relevant ability, or make it not share damage. 

@CursedParrot, I really like the flavor and design of Luna's Cosmic Portal, though you could make the wording better. If it said "After you cast a spell, store a copy of it and lose 1 durability. Deathrattle: Cast the stored spells" then it would read a lot smoother. But if you can think of a more official sounding word than "store" to describe it saving the spells than use that instead.

@Pokeniner, Kirin Tor Astrologist is my personal favorite, but it may not be your best card. The wording on Nether-terrestrial is a lot better now, that card is my second pick. I don't really like Extraterrestrial Arcane because I don't think it would be very useful in a practical sense. How many Elementals are you going to be able to play in a single turn? 4? 5? And how much tempo are you losing because you are holding back half of your hand? And is it even worth it just to get a single above-average spell? If it is part of a custom expansion then I could understand that archetype getting more support and maybe working, but in a vacuum the card is weak.

@Hordaki, I really like the flavor, but I am not sure about the 7 mana 7/7 statline. I get that it is Dr. Boom, but 7 mana 7/7 may be a bit too good in too many decks. I would put it into a class, maybe Priest or Mage. Instant removal like this probably shouldn't be Neutral.

@TheHoax91, I don't know if you have looked at the submissions yet, but there are at least 2 other Algalon the Observers. It is totally fine to have the same character submitted more than once, but when the same name and art appears 3+ times it doesn't look unique or inspired any more. I am not saying you can't go along with this card, but just keep this in mind. About the actual card, I like the second version better. The two abilities of the first one don't really seem to connect, it feels like you just came up with some form of restriction and then some generic form of payoff, the second one feels more focused. It is a tech card, that is what it does and it does it well.

anchorm4n, is this effect until the end of the game? If so then it should say on the card, if not then this is a worse version of Violet Illusionist. If it is a permanent effect than this is a really cool card, but it does seem a bit out of place in Priest. The only time you are taking damage on your turn is when you are in fatigue. Maybe if this was a neutral card?

Linkblade, I like Meteor Fall a lot. I am not sure if it would be a very good card unless it said random minion instead of random character, but the flavor is there and it does look like a card Blizzard might make.

Demonxz95, For Celestial Crafter, you don't need to say "with the same cost as the chosen spell" you could just say "with the same cost". That aside I think Starace is better. Though if it is supposed to be pronounced "stariss" than it should probably be spelled like that. As it is now people are going to pronounce it "starace". But that is a minor thing. About balance, I think at 3 mana it is just too expensive. I think 2 mana spell damage +2 is fine.

Xarkkal, Planetary Alignment is probably too slow to be good. It is really hard to set up a good combo because you don't know what you are going to have drawn at that point. It has the potential to highroll and set up a big swingy win, but you also may very well draw wrong and the card is useless. I would maybe reduce the cost and effect of the card so that it is a bit more reliable, and has less potential to swing the game out of nowhere.

BasilAnguis, I like Gravity Well a lot. It has solid flavor and it is playable.

Wailor, I like Space-Time rift best. You can use it in a lot of ways, and it would probably create some combos which is always fun. 4 mana may be kind of a lot though considering it is only going away for a single turn. I would make it 3 mana.

MenacingBagel, The card is probably too slow and expensive for what it does. I have played enough [Hearthstone Card (Swamp Queen Hagatha) Not Found] to know that 7 mana 5/5 add high value cards to your hand isn't usually worth playing. Maybe if it were a 5 mana 4/5 add 2 portals?

Bloodmefist, Even Horizon is okay, but probably too similar to Twisting Nether. Color From Space is cool, evolve stuff is always fun. And this also won't create stupid shenanigans with Desert Hare. Algalon the Observer is interesting, but it breaks the rule of Custom Hearthstone, no more than 4 lines of text. I can see why you added that last bit so that Mages don't cheat out anything too big on turn 3 or 4, but it also makes the card too wordy. I would make him a 5/5. All in all I think Color From Space is your best, with Algalon as a close second. Though both could use a little bit of tweaking.

shaveyou, I like Homemade Shuttle, but I don't see why it needs to be a 4/4. I think 3/4 is better so that it still has strong stats for 3 mana without having too many stats. Also the 3 attack matches the 3 damage it deals when it dies, which emphasizes the fact that it crashed into something.

Pokeniner, Extraterrestrial Arcane is interesting, but I think it would be simpler if it just dealt a random damage for each elemental instead of adding spell damage. Kirin Tor Astrologist is probably too slow. I would reduce the numbers, or maybe make it discover an 8, 9, and 10 cost minion. Nether-Terrestrial is interesting, but the wording is weird. Why not just say "Battlecry: Give a minion 'Deathrattle: Cast Twisting Nether'"? It would reduce the amount of text by a lot.

MenacingBagel, I think Reveler Reno is a better card in a vacuum, but Firework Fanatic is better flavor-wise. But they are both good cards.

Linkblade91, I really like this card. It is both flavorful, and it looks like a lot of fun to play with. The only issue I have with the card is that it destroys all of your armor, so if you already have 20 armor stacked up, playing this actually deals damage to you. Maybe you could change it to say "deal 85 damage to your Hero" instead? But that kind does kind of make the card a bit clunky. 

Alfi, Don't forget a watermark! Aside from that the only thing I would change is reduce the number of Hellfires to only one and maybe make him a 7/7. I understand why you have two Hellfires, but as it is you are giving your opponent way too much. Just look at King Mukla, he has the same stat bonus (+2/+2 more than the cost would imply) and he gives two bananas (which are worth much less than Hellfires) and he is still too bad to see play. 

anchorm4n, Great card! Grammar is good, flavor is strong, it is playable in a lot of decks. A solid 5 star card.

Wailor, I like Happy Hour the best. It might be a bit dangerous with Rogue playing so many cards in a turn, but for this competition I am a little less concerned about how powerful the card would be if it were printed right now, and more concerned on the flavor of the card.

Dermostatic, I really just don't know about this card. It is funny and all, but some people might not like the fact that it is super unrealistic. Go along with this idea if you think people will like the joke, but if people are going to be taking the cards a bit more seriously, then you may want to come up with something else.

MrRhapsody, I like Whine and Cork Shot the best. I would make it 2 mana though for balance reasons, and maybe make it restore 4 Health instead? Right now I feel like it is a bit too efficient for 1 mana.