Mass retail - but that is just me wanting to see everybody getting a good chance to know about and buy Transformers.
Could it sell at retail? That would be a gamble. I think Transformers drop so much ball with cross promotion it is not funny. A help would be stocking cheap, compatible legends figures that can cross sell Metrotitan on their card backs. Release Metrotitan surrounded by the smaller figures on shelves. This titan class has to be shown to kids (cardbacks, tv ads, tv show spot). They need to know it exists, dream about it, hound their parents to buy it. The backing art for G1 toys was perfect for this - seeing 15 toys battle it out made me want them all.