Hello! I registered here to hopefully provide some useful feedback on this thread. I'm a marketer by trade and am developing my first indie game. I don't have much time but I did want to help a fellow indie dev, so here are a few one-liners for you. Take em or leave em.
1) Finding your elevator pitch is a matter of focus. Focus is a process of cutting.
2) Cut what you can't pitch. You can't pitch visuals without visuals. Or references. Either find another popular thing you can compare it to or gloss over it.
3) Draw attention to experiences rather than features. Have you ever wanted to be on a team of 5 mechanized spiders fighting against 5 other spiders who are trapped in Attack on Titan meets Ender's Game? Note the use of the phrase "have you ever wanted to" - take your audience to their mind palace.
4) Don't be afraid to compare your product to other products* so long as you genuinely feel your game captures the same emotions as the other product.
5) *BUT NOT OTHER GAMES. You don't want to get trapped backpedaling or being perceived as conceited. Only ever compare your apple to someone else's oranges. Added benefit: building uniqueness.
6) Build uniqueness. Only talk about the things that make your game unique. You got that part down, keep doing what you're doing.
Sorry so brief, hope I helped. Test different messages. Get volunteers to post different messages on Reddit etc and see what works. Good luck!