Orange Sun enhances Tiberian Sun & Firestorm greatly including campaign and increases the gameplay possibilities while remaining the original feel of the game. Basically a rebalancing together with new content and lots of spleen. Now features the Campaign+ modifications.
The walker in here is the new look of the Cyborg Reaper. Its original is LKO's Redeemer. It has the web attack and a grenade launcher working very similar to the rockets you knew. The Monolith is a hero unit that when it dies leaves this huge explosion with a rather huge splash damage.
Those who have played old versions will recall the circle of fire from the monolith. The explosion over the tank is an early stage of LKO's fireexplosion caused by an artillery shell hitting it.