This game looks... Good ._.
It's seems like a fun, cute and exiting game, and that's honestly all you ever need. Wow.
The set seems pretty cool, I'd have to see the other Arceus to see whether or not they may be viable, but the water and metal one will most certainly help quite a lot.
When I 1st saw that Gengar, I was like "OH NO, NO NO NO", then I read what it did and just lolled. Seriously, I almost thought they were going to turn that already scary monster into the Hulk or something. Sure, it might be cool, but it probably won't help Gengar decks as much as it could have. Some guaranteed damage should be appreciated by Gengar, though.
The best card in this little group has to be Charizard, though. Finally a Charizard with donk AND swarm potential, that's pretty sweet. It's also more damaging than Kingdra, more certain than Machamp and less vulnerable than Rampardos. If they add some more fire support this thing might end up being a real beast and a force to be reckoned with. The Charmander doesn't seem bad as well, better than most regular basics.
Salamance lvX's picture looks silly, and that power just screams "Power Spray me!". But if your deck can't do that, good game. The regular Salamence in this set is cool, but I think SF is the obvious option here, using both shouldn't hurt too much, though.