Start by counting how many weeks you'll be teaching for, and decide how many countries you wish to cover. You'll need this to know how many pages to staple into the "passports" anyway. Once you've figured that out you'll have some idea of how many lessons per country there'll be. From what you've said, I'm guessing 3-6.
Keep the schedule consistent. Routine is super important at that age. They love repetition.
Next, sketch up a framework for each country. If you've got three lessons per country do something like Intro/Motivation and New Song, Vocab and Speaking/Listening Games, Arts and Crafts. Do the song early on so you can review it each class alongside your "Hello" song(s). Another option for a lesson is Storytime and Colouring In. Plenty of good stories online for ESL learners or just pre-primary kids that you can adapt; Google Image Search illustrations if the story lacks them. If you're really short on ideas, slip in the alphabet, one "featured letter" per nation. A solid lesson plan for this age group might be a 10 minutes Hello and Songs revision section, and then either three 10 minute blocks or two 15 minute blocks of stuff (crafts may necessitate multiple blocks). Don't overthink it. Draw up a grid with these time blocks on it and just plug an activity in each square. That's your lesson plan, done.
Nut out the target vocabulary. For each country pick a couple of foods, a couple of tourist landmarks, language (the words for "Hello!" and "Goodbye!") and maybe something else like traditional clothing. Aim at no more than 6-8 pieces of target vocabulary specific to each country to avoid overwhelming them. Besides that, you can squeeze in just about any target language you like alongside each country. "How many X?" with numbers 1-6? Find iconic imagery from the country and have the kids count objects in each photo. Colours? Iconic imagery with dominant colours.
Honestly, the hardest part is the recommendation that you come up with a relevant thematic song per unit. I mean, you'll have to be super creative to shoehorn simple nursery rhymes and folk songs in. I'm thinking such straw grasping as
10 Little (German) Sausages or
Wheels on the (Red London) Bus Go Round and Round.
Games:
PinMagnetise the TailCountry on the DonkeyMap- Flyswatter Game
- Ball Toss (Target)
- Four Corners
- Whispers
- Bingo
- Slap Game (Cards)
- Memory (Cards, can match icon to flag, say)
- Tag
- etc etc
Tonnes of low tech games banks out there for young learners.
Teaching English to Children in Asia has one. Look up Japanese ESL sites, because they don't use Powerpoint over there so its all super simple low tech reocmmendations. The chap who runs Genki English has a tonne of simple game explanations and video demos out on the web.
