Hearthpwn

This my version of the mech-mage, for a weapon heavy meta. The most recent build works very well, and has quicly brought me from rank 7 to rank to rank 4, eventually peaking at rank 2 last season. Unfortunately, I was unable to play enough games to get legend, but I believe the potential is there.

The main concept is to use the synergy between Mana Wyrms and spare parts rather than secrets and Mad Scientists.  I have had Mana Wyrms grow all the way to 7 attack if my opponent is underestimating them! Also, Harvest Golem is an amazing card in mech-mage, which I do not understand why is getting cut. It gives much needed stickyness to the board, and can guarantee usually Goblin Blastmage value better than Spider Tank

Harrison Jones is a flexible card, and Piloted Sky Golem, Sylvanas Windrunner, The Black Knight, Polymorph or Azure Drake can all be good replacements. I try Harrison Jones for now because it fits well with the curve, noone will play around it, and does not hurt much in the mirror matchup. Even against druids, he does a good job at clearing up taunts or pushing for lethal.

Mulligans:

Always look for: Mana Wyrm, Mechwarper, Clockwork Gnome

If you have a good curve with a 2-3-4 drop, it might be worth keeping the hand, even without the premium early-drops above.

Vs rogue, I have a lot of success keeping Piloted Shredder and Harvest Golem, because they have a lot of trouble killing them off, but good rogue players knows very well how to use their AOE and removal to dominate the game. However, you can cripple him with Snowchugger, and by playing Loatheb and Harrison Jones at key moments.

Vs zoo and hunters, I like to keep Goblin Blastmage, because it is such a strong tempo-play, and a win condition in itself. A very difficult matchup is midrange hunter, as Savannah Highmane gets too much value while Freezing Trap is slowing down the earlygame.

This deck will generate a lot of spareparts, so the chance of drawing Finicky Cloakfield for the ultimate turn 8-play is pretty high.

The sparepart game:

For me, this is a very interresting part of this game. Pretty often, I have seen myself triggering spareparts before making my moves to search for specific solutions and plays. Spareparts can be win-conditions on their own, so make sure to account for their effects, and use them well! I am still learning this, I believe the skill cieling for it is pretty high.

EDIT: Mechanical Yeti is cut in a crowded 4-slot, and my opponents spare part some times hurt me. Trying The Black Knight in its place because almost every deck seems to taunt up now.

EDIT2: The latest change proved to be very good in this meta, and this deck has now brought me to rank 2 EU, expecting to reach legend soon. My winrate for all games this season is 57%, but it has actually gone up moving into the higher ranks.