Someone with a fairly highly rated comment said you will get the high score easier without worrying about crystals. False. The only way to get there is to keep your speed up AND look for crystals. You can get over 40k on the final level by focusing on crystals but will struggle to break 25k if you just try to play through.
Nipple Gobbler, You spent 20 dollars on crystals for this game? What is wrong with you? You know real games exist, where developers proofread and check glitches and the graphics actually use your video card's capacity, right?
If you take your hero straight to the right edge of the screen then sword chop off the screen while not moving, you can block all of the new units for the other team but not take any damage. All levels become very easy.