While the gameplay isn't completely terrible depending on the race you play (I beat the game attack drone race which wasn't bad, then tried starting over as the Wyr whose aoe weapon requires you to stand still and charge the distance you're throwing the grenade which makes it practically unusable), late game mechanics are so repetitive that the game isn't really worth playing. As the game goes on the enemies and enemy buildings/turrets/etc become stronger and take more shots to kill, increasing how tedious everything is.
After you reach max level and become the leader of your race, you can command attacks on enemy bases and space stations, which you personally have to lead. You can only command one action at a time, which causes everything to move extremely slowly, and you can't combine the forces of multiple stations.
The enemy AI isn't that great either, once you power your ship up enough you can repeatedly do attack runs on the enemy station practically unmolested and win the battle while everyone else is flying around shooting each other. Enemy ships don't seem to target you or try to follow you, they just seem to shoot at you if there's nothing else nearby to shoot at. The ground missions aren't a whole lot better, other than the targeting on the enemy turrets is so bad you can just keep slowly strafing and they'll never hit you.
All in all, I like the concept behind Salvation Prophecy, but it really needs better enemy AI, better mechanics, and more improvements to your ship that you can make after halfway through the game.