Freeriding. Don't be deceived by this mountain's name. At only 1,050 metres high it is no Mont Blanc. Its trees are too thick and the natural snow in this area too limited to allow for much free riding.
Freestyle. Pheonix Park was one of the first resorts in Korea to target snowboarders and now maintains a nice Super Pipe and a pretty decent terrain park. Both can be reached using the Hawk lift at the top of which you'll find a good array of rails and booters leading down to a few really solid table tops and one of the best half pipes in the country.
Even when the rest of the resort is overflowing with people the park is pretty uncrowded aside from a few trendy Korean guys and girls displaying the latest gear. Let it be known that even though snowboarding and the time needed to go snowboarding are to relatively new things for Korea's youth, they have attacked it with gusto. Spend a moment as a spectator in the terrain park and you'll see some innovative, technical manoeuvres thrown down by the locals.
Beginners. The main worry for beginners will be dodging the thousands of other beginners hurtling out of control over each others skis and boards and into spine crushing collisions with other people, trees, rocks and fences. Aside from that and the slightly steep Paradise Course the mountain should be fairly manageable.
A snowboard school is available and though English speaking instructors can be found, I suspect that their instruction might do more harm than good for your snowboarding. It is interesting to note that in Korea snowboarders are expected to remove their boards before catching a chairlift eliminating the difficult task for beginners skating your board on and off of lifts.