Answering from the other side, I run a small indie review channel (@NoTimeForReviews on YouTube). What gets a game played on mine: the dev emailed me directly, the game was close to something I'd already covered, and the message showed they'd actually watched a video. That's it. Press kits and store page polish matter less than people think at this size.
What doesn't work: posting in threads and waiting, or mass emails that open with "Dear creator". And for what it's worth, I'm building a tool that finds channels by what they already covered, because the finding is the part everyone gets stuck on. Not open yet, but it's called coverMyGame if you want to look it up.