Don't worry, as the achievements can technically be completed even if you suck at the game. No fancy formatting since I'm too lazy for that, but here's the info you need:

Achievement Roadmap:
Happily Ever After
You get this for completing the single player. The game is not that hard as long as you realize that you can control the ball with your mouse even after you throw it.

Tricks and treats related achievements.
Pinball Wizard
Dead Meat
The treats are easy, as most of them are powerful enough to get you a strike if you just smash the ball somewhere in the middle of the zombie.

Anarchy
Shields Down, Captain
Sneaky
Dance Fever
The trick can be a bit more.... tricky, and they'll require you to counter them with the right treat. Ice blocks, ball with arms or rocket should help you get the strike for all of them.

Now of course, getting those treats or getting those tricks used on you is a matter of RGN... unles you use the Vs. Living Beings mode. Start it up and select Set of Bonuses mode. Reroll them untill you see the tricks and treats you need. Use the trick on yourself as a guest and score a strike as your character. The achievements unlock in this mode too.

Fair Play
Same as with the previous one, just start up a local co-op mode and don't use any tricks on yourself as the guest.

Carnival Game
This one could be a bit tricky as I'm not entirely sure about the conditions that unlock it, but I got it after hitting strike with the ball with arms making all 10 zombies fall into the pit behind them. Basically, don't let any part of the 10 zombies be left on the lane.

Strike count related achievements and free play mode:
Now, you could technically manage this by being really good at the game, but that's not very probable, is it. So you're going to cheat.

The way to do so was brought to us by Ha Ha Ha Thud!!! in this guide: https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=250635184
Basically, you'll edit some file and get yourself a large and heavy ball and lined up zombies that will guarantee you a strike unless you deliberately try not to get one.

Start up a Free Play mode which requires you to complete ten games with an increasing minimum score. Just throw a strike with each throw and you're golden. You can play "no bonuses" mode to make it easier and quicker.
This will net you:
Agility
Rookie Striker
Experienced Striker
Strike Master
Strike King
Marking Pen
Bi-Centennial
300 Club
1000 Club
Freedom Fighter

That's all. If you have any questions drop them in the comments below.