In it's basic gameplay mechanics/ideas, Bloodline Champions is similar to DotA/LoL/HoN. I think it's also a lot more fun because it does away with all the 'farming' and 'snowballing' and the like. It's pure arena pretty much, though there are also CTF and Conquest modes.
Biggest differences are that there's no autotargetting, if you land an attack/ability it's because you timed it or placed it right. There are no items or gold, every champion is roughly equal, though through patches they wax and wane inevitably. Matches are much shorter, with a best of 5 arena (the 'base' game mode) usually taking between 5 and 10 minutes. Fewer playable champions, but they're much more developed and more intuitive going from one to another.