As it is now, it's pretty rough... The enemy with 3 runes almost turned into a stalemate. Then the next enemy with 4 runes just OTKs me before I got to move... ouch.
The enemy pixel art itself is fine, but the excessive linear scaling makes it very blurry. Try resizing the textures up in another program (e.g. paintdotnet) with nearest-neighbor or sharp filter, then let Defold linear-scale it the rest of the way. Or use a sprite material with a shader (which could be hard to find and/or time consuming to learn).