In terms of difficulty, LOT in normal mode is easier than GOT to complete, you have a lifebar, you can buy elixirs or shields, in GOT, if you loose a life, it's almost over...
But GOT is a little easier than WOT in higher difficulty levels, if you completed it in normal you can complete it in hard or devil mode with some training. The game gets really fun and exciting in harder modes, with more ennemies to deal with and frenetic action. WOT in harder modes adds tons of bullets, and the difficulty becomes insane with some levels and bosses.
Both are fantastic, but GOT is my all time favourite game on any support, so it got (ha ha) my vote.