I made it almost to the end of the game, I speak a bit of Japanese and I can read kana but the game is very simple all the missions have similar objectives you just need to get the hang of it. I'll try to write a little guide.

The objectives of the quests are highlighted at the end of the quest's description so to know what to do you just need to read a single line. The objectives can be: kill all the citizens (subete no shimin wo yacchau), get all the treasures (subete no takara te ni irete), get the big treasure (ookina takara wo te ni irete), do a certain number of combined attacks ( number konbo... written in katakana), kill a specific character usually a boss ( character name wo yacchau) and destroy all the crates/cars/tents/ etc you need to translate this one because varies from mission to mission you can recognize it because there written kowarete (destroy) after the name of the item. I've haven't got the game with me right now so the descriptions I wrote might be slightly different from those of the game but still recognizable I'm sure I got most of the words right.

I did a couple of quests that were a bit tricky, one of them asks you to make two characters meet they had a heart icon on their head while in another mission the citizens were damaged only by exploding objects.

Some quests have terms you must meet like a time limit or limited touches of the screen the terms are written right under the quest objective. To access the quests you need to touch the blue or yellow bubbles over the zombies in the farm. The blue bubbles are side quests while the yellow ones are main quests. There are also pink bubbles that tell you what kind of item that zombie would like to eat you'll need to translate this one but it will be just fine even if you don't give them what they like.

The seeds and the items are divided into groups by color red is for attack, blue for hp, green for defense and yellow for speed I dunno if it affects only movement speed or also attack speed. When you touch them you can see the values no need to translate here.

Then there's the skill forest where you learn new abilities. To unlock them you need to attack the rocks with the required number of zombies, written on the rocks, at the same time. So if a rock has 35 written on it you need to send 35 zombies to attack that stone at the same time, the rock then will break and free the path to the next area of the forest where you find the new skills. You might wanna translate the descriptions of the skills because some are straightforward like healing and resurrection while others are passive like increased damage from back attacks.

To use the healing and the resurrection, you need to find a special golden treasures in the levels. Once you find them the icons of you skills turn on and you can use them. The resurrection lasts only 10-15 seconds after that time the zombies will die again instantly so you'd better use when you have only 3-4 zombies it's a good tactic to kill bosses.

Completing quests, you'll get a carnivorous plant a cow and additional slots to plant seeds. If you feed it, the plant will unlock new power ups for you skills while the cow will combine 4 seeds to make a rare item (sometimes it just makes crap items dunno if it's random) If you want you can press omakase at the bottom of the items window and the zombies will plant the seeds randomly.

There are cameramen in the stages if they see you, they'll start to broadcast the attack and once the REC level, on the upper screen, reaches the maximum a SWAT squad will be sent to exterminate your zombies.
You'll see an helicopter icon that replaces the rec, when the helicopter reaches the map the SWAT squad will spawn in the stage. The SWAT so far is unbeatable, they deal 50 damage with each shot, your zombies will be decimated in no time therefore you must either attack the cameramen or run away from him. If you attack a cameramen you can only make him faint, after 60 seconds he will restart the recording.

I haven't finished the game yet but that's pretty much all you need to know, the game is very simple you don't need to read much. I didn't read the post it might be filled with typos sry.