The first two modes pretty much equal a Skullcrack since the Command cycle allows you to choose two of the four modes. Losing the damage prevention restriction and adding the ability to hit each opponent isn't a big deal. The each opponent addition does seem odd to add to me, as this isn't a card I see being so good in a multi-player format. But it’s there all the same.
How about the other two modes? The ability to play a land card straight to the field is an interesting option, and it probably will be the most rarely used. Still, I wouldn't rule out using it, especially as that land could come in untapped. The last mode may easily be the best: giving creatures you control +1/+1 plus reach until end of turn. Reach is actually pretty good since Red/Green does have problems with flyers, but that would mean using this card defensively in decks that want to focus on being constantly on the offensive..
All that being said, Red/Blue/Green tempo decks, popularly known as RUG or Temur tempo could find a home for it. I see the first two modes and the last two modes being used together the most. Who expects a land drop at instant speed? A copy or two might sneak their way into some Modern lists, as well. RG Devotion and aggro might play a copy or two in sideboards against things like Siege Rhino, a card which is also played in Modern. It’s also good for preventing the lifegain given to opponents’ burn spells from Soulfire Grand Master and the lifelink from popular creatures like Seeker of the Way..
There are enough incidental life gain effects in Magic now that a card like Atarka's Command is a solid tempo card. Skullcrack is still better in Eternal formats, but this Command should at least see some solid play during its time in Standard.