I like that you're creating a unique spin of a familiar concept. I love the idea. It's clever and I like, but it might be too clever for a general audience. What strikes your imagination more: Dragbol or Dragon Symbol?
The downside of using a unique name is that it will be harder to gain traction because of lack of understanding.
Nobody knows what a Runome is. People have no preexisting attachment to the concept of a Runome. Growing up, we have experiences with concepts which we can easily latch on to later. Take the cultural obsession with Vampires, Zombies, Pirates, etc. Or, more relevant is the reuse of elves, dwarves, dragons, etc. in fantasy settings and games. I'm not in any way saying new races or creatures can't be successful (Avatar had new creatures and was incredibly successful) - my point is that people will have an easier time identifying with something they've already been exposed to and are familiar with.
A ton of games and clones of games exist on the App Store. How does someone pick one? If you know the game is about gnomes (or whatever you can identify with), you have hints about if you'll like the game.
So, the only real downside is that I think it will be harder to gain traction. It sucks, but it's up to you if it's a big enough consideration to change the name. You can absolutely create a unique name and successful, it will just be harder. If you do decide to change the name, there are a lot of ways you could hook into preexisting concepts, while still being unique.
Everyone knows what runes are, everyone knows what elements are, and everyone knows what gnomes are. It seems like those are some main concepts of your game, so you might find it easier for people to connect with them if you amplify the concepts individually.
Nt that you should call it this, but to illustrate the point: Runomes is more clever, but Rune Gnomes has absolutely no ambiguity around what the game is about - plus, it's unique (what happens when runes and gnomes are combined?)
Runes evoke a sense of magic and mystery. Gnomes are universally known, and probably evoke a sense of a whimsical small creature (heck, Expedia's mascot is a gnome). Tangentially - when I think gnome, even with my EQ history and whatnot, the image of a sort of garden gnome is stronger...just an example of the power of commonly used symbols.