Coming from someone who is not a Mortal Kombat veteran, I give it a 3. The online trophies are pretty difficult (depends on who you`re fighting). Mortal Kombat and Mortal Kombat 3 are kinda difficult, But Mortal Kombat 2 was very hard. Beating all the games was quite the adventure, but if you played it on very easy it should have been achievable.
PSN name - g_v_n1234567890
- inFamous, inFamous 2, Little Big Planet, The Walking Dead, Far Cry 3, PlayStation All-Stars Battle Royale, and Heavy Rain
100% - Mortal Kombat: Arcade Collection, Hamster Ball, inFamous: Festival of Blood, and Kung-Fu Rider