Never heard of Hopmon. Is it fun?
I played one Digimon game, but I don't remember much about it, as I much prefer Pokemon. Digimon had a bit of Tamagotchi to it, you have to feed them. And Digimon evolve only in tough battles to be stronger and afterwards they return to their former self, while Pokemon usually evolve once they reach a particular level (although some evolve when you either use particular stones or trade them and in one incident with Inkay, hold the 3DS upside down in a battle where Inkay has reached enough exp points to evolve with the points it gets from that battle; not kidding, the 3DS has a gyro inside so it detects the movement) and once Pokemon evolve they remain as what they evolve into and can never de-evolve.