This guide is for those who may struggle to find a solution for "Cube Strike" like I did. At the time of making this guide, there was no guide to help figure out which level was best for this achievement. I won't lie, this will likely take many tries, but this guide should help getting this achievement much easier.

The achievement requires you to hit two monsters with one cube.. slightly misleading, it actually means to kill two monsters with the same cube.

I didn't bother making a guide for any of the other achievements or adding them to this guide, simply because they are pretty straight forward on how to get them, with enough tries, you'll get them no problem; This achievement was the only one I found challenging with no straight forward solution on how to get it.

You may be thinking, "how would I ever get the same cube to kill two monsters.. getting clouds to disappear at the right time so the cube not only hits one monster, but to hit two that are only one hit away from death is next to impossible!" This guide will help!

I went through all the levels and there are actually a few you could do it on. The best one I found that worked for me was

This level has the cubes continually moving until they hit something, this is great for us! There is another identical setup on level 62, however you would not be able to spawn as many monsters.

Wish I could tell you a straight forward step-by-step way to get them hit by the same cube but it does require some skill and practice.
However here are some useful tips I learned:

• AVOID getting upgraded balls/any weapons, you want to avoid getting all the upgrades because you do not want to use anything that could accidentally hurt the monsters and kill them. Only exception is if you need to quickly use a ball to kill a bat.
  
• If possible, spawn only bees, as they will usually always follow you.
  
• Stay (generally) in the bottom right of the level. Remember that cubes will likely fall off screen if they are hit on the top path they take. This means you want to stay in the bottom right so the bees will come at you while you move out of the way so they get hit by the cubes on the vertical path; so the cube falls back on the arrow so they don't fall off the screen. When the cube is on the top path, it's moving away from the bees = less chance to kill a bee and have the cube fall off screen (though can still happen).
  
• If only bats and crows spawn, just restart the level at that point because the bats will likely drop all the cubes and crows usually are too high to get hit by the cubes. (However, crows can sometimes be okay; the monsters that got me my achievement was a crow then a bee).
  
• only keep two monsters on screen at a time; don't want to cause too many problems with cubes dropping.
  
• You can hit all but one cube off screen so you know for sure that the same cube will hit the two monsters; I wouldn't do this until i saw which cube was the one to get the first kill.

Optional Tip (though I didn't actually do this when I got the achievement):

• You can hit a monster 3 times so their final hit with the cube kills them. However, I would only do this if you have one cube on the screen so two different cubes don't kill. This might also be more frustrating than its worth because sometimes an unaccounted for ball that you used could just kill the monster; which is why I personally didn't use any balls for damage and just let the cubes do all the work.
  
• If you want to do some damage to the monsters, use a boomerang only. This is so you can better control how many times they get hit and there are no stray balls bouncing around the level

When to restart is mostly based on having only 5 monsters that can be spawned.
Restart when:

• All the cubes dropped off screen
  
• If no bees spawn / only bats and crows spawn
  
• The cube that killed the first monster falls off screen
  
• No more monsters can spawn
  
• Too many balls flying around the screen / killing monsters

To sum up what you will be doing to get the achievement in case it wasn't clear:

1. Replay Level 162
   
2. Spawn two bees if you can (restart if not bees)
   
3. Stay in the bottom right of the level till one of the monster dies from a vertical cube (avoiding their hits also)
   
4. When one of the monsters dies, make the other cubes drop off the screen (or do this first, however could take longer)
   
5. Get achievement!

I know it could take many tries but if you learned something from this guide, I'm sure you'll get the achievement! Good luck!

If this guide helped you at all, consider leaving an Award. Would be much appreciated!