What I did was

1. Play Tundra Rhino
2. Swing a hydra in to the middle minion, leaving 3x 9/5 and 3x 1/1
3. Windfury Tundra Rhino
4. Clear the leper gnome in between the 1st and 2nd minion with Rhino
5. Windfury a Hydra, swing in to the Leper Gnome between the 2nd and and 3rd Minion, then swing it again in to the 2nd Minion. Leaving you with a 9/3 and 2x 9/1 and 4x 1/1
6. Coin and Windfury last Hydra, swing in to leper Gnome between 2nd and 3rd killing 2nd and third and then swing again in to the first minion making it a 9/1 and 3x 1/1 left.
7. Tundra Rhino in to last 9/1 and 3x Engineers in to 1/1’s, should leave you with 1 hp since you only killed 7 Gnomes.

What I did was double Radiant Elemental, Test Subject.

Vivid on Test Subject and Topsy Turvy, repeat a second time.

Vivid on Radiant Elemental and Test Subject and Topsy Turvy Test Subject.

So my board then was 2x 2/3 Radiants a 2/1 Radiant the 1/2 zapper and the 0/2 Test Subject. And hand should have been 4x Smite, Topsy Turvy, Pain, 3x Vivid if I remember correctly.

I cast Vivid on the 1/2 zapper thing, topsy’d a radiant to make it a 3/2 and pained the 2/3 radiant and cast holy smite on the test subject which gave me back a 4th smite and left me with a 1/2 zapper, 1/1 zapper 2/1 radiant 3/2 radiant and 4 smites, cast smite on one of the radiants then both the zappers and the last radiant and it was over.

I’m pretty sure that’s how it worked out for me, definitely needed to cast a vivid on the zapper once to get enough pings on the enemies and be left with 4 minions to clear with smite.