Game is very good, especially for F2P. The actual gameplay is a pretty unique approach to the light-strategy/card game hybrid. There are timers for acquiring and training new cards and the like but no energy timers or anything, you can play to your heart's content. Game starts you off with all you need to get going and running through the challenges will net you a bunch of new cards. New Heroes can be acquired through several means but the main two after exhausting the challenge levels is through a chest purchased with premium currency, which gives a random hero, or through a selection of three that refreshes every 12 hours and is obtained through the standard currency. Both currencies are earned through play as victory prizes and achievement unlocks. You can use the premium currency to reduce the wait for the Hero refresh or you can use the "Soul Timer" which is an amount of time that automatically builds that can be spent to reduce any wait timer as you see fit. All in all, given how many cards and heroes I have acquired after a couple days of play, I feel like I have plenty of deck-building options already and have not felt the need to spend any money at all. There is a good amount of depth here while also still feeling breezy.
Not really sure why this game doesn't seem to be gaining traction. Game has depth, interesting mechanics, cool art direction and themes and a generous F2P model. You can make Abraham Lincoln fight (or team up with) Dracula.