Thre are two things to really consider here: the first is obviously "is this really worth continuing to promote?" The answer to that comes in two forms. Is the game generating sales from my PR/Marketing efforts? And what is causing or preventing that coverage.
The fact is that not all games are worth promoting and the review scores may be disconnected from sales "scores" - so first compare what you are making per view generated!
Is your game generating strong appeal to casters? If so, focus on making yourself visible to them, especially via social media and if possible in person. It's the same plan for major publications but strangle more difficult and less impactful.
Next up, plan an event. Not a live in person one, probably - but it may be time to use the secondary market for a second wind. Let's say you get into a good bundle. Using that you coordinate a push to have casters drop videos and help promote the sale. Timing a sale to pr is a huge deal. Then hopefully ride that renewed interest in the product to pick up review/news/casters you missed befrore. Rinse and repeat this process till it stops working or you die
Ps: apologies for typos, writing this from my phone while waiting for someone :D