This is still a little underpowered, but it's a good step towards a stronger deck
For three mana, that's not the greatest rate in the world, but there are plenty of targets in multiple formats, and finding ways to get more interaction into your decks is always good
With their own deck and special card back, Contraptions are a complex mechanic only otherwise seen on Steamflogger Boss
Scale Up [G: Hit for Six] Scale Up is one of the cleanest power spikes green has
The backside, while just a 3/3 that dies to all the popular removal spells in Standard, has a very powerful ability for a go-wide deck by giving all your noncreature spells convoke
2 Mike, the Dungeon Master Mike, the Dungeon Master is a 2/2 human that costs one generic, one green, and one white, and he is an absolute powerhouse You can pay two generic mana and tap Mike to return a creature that was put into your graveyard this turn straight onto the battlefield