It's much easier. Many skills are available from the beginning, you can jump higher, swim without running out of breath, survive any fall and can fully restore your health bar by repeatedly repairing yourself after running out of syringes.
The game is about 7 hours for 100% completion, but the story itself is very short. For the asking price, it's still pretty good value.
"You think I don't know you - what you're about? Wake up - I used to be you." - The Jackal, Far Cry 2
It's pretty easy (even if you tweak the difficulty mode). Considering that the graphics are really toned down and you level up far quicker than Jason in Far Cry 3, the games are similar yet different in many ways. BOTH games are uber fun IMO