Go Take A HIke!
It is, as the description says, Big Two with tiles. Big Two and Tichu have similarities but are far from the same game. Differences: in Tichu you have to play the same combination; played in partnership; scoring works differently; 4 "jokers" with special abilities.
I'll second that. Much different games. Rooted in a common ancestor sure but the partnerships, when to pass the lead to your partner, what cards to swap, etc. all make it a very different experience.