While it can also benefit your opponent in two-player formats, it becomes highly exploitable when your deck is built around massive creatures
It does not, for example, change when you may activate abilities that can be activated "only as a sorcery." The last ability cares only about the amount of mana that was actually spent to cast the spell, regardless of its mana cost
Claim Jumper has the potential to get two Plains out of your deck
Enthusiastic Mechanaut Enthusiastic Mechanaut falls in line with Goblin Electromancer and other cost reducers, but being the card type it also interacts with pushes the synergy just enough to deserve a higher ranking
Its interesting that you draw and get to use the cards first while draining your opponents in the process
I've got a few impulse draw triggers in the list, but it's safe to say that card draw will be a challenge without including cards outside of the Spider-Man set