The map to get around to the different countries would, of course, be a map of the world. The main goal of the game would be to "form an alliance" with the country of your choice, though if you get negative heart points with a country, you can also get into a war. You can buy items like pasta, burgers, tea, sushi, and wurst (I'll let you figure out which country likes what for yourself), and also armbands with the countries' flags on them. For instance, if you buy and wear the American flag armband near America, he'll like you more.
Standard two dialogue choices, the option to Trade (exchange gifts) or have a Cultural Exchange (a date). There would be a special event for each country (ex: with America, meeting his alien friend; with Italy, he talks about how he wants to be stronger; with England, he talks about losing America but being happy now that your country is here.)
So although it doesn't seem like I held back at all, I have a lot more ideas, though I want to leave a lot of creative freedom to all the awesome people who might end up helping me out. So I can note all those interested with some more of my nitpicky ideas. This is a project for several people, so please, awesomely creative people who want to have fun, join this project to make an amazing Hetalia dating sim!
EDIT: To all you lovely folks who have commented, I don't want to leave you hanging, so... The game is still in production, but I have uploaded the concept sprite art for 5 of the countries to my deviantArt. Check it out if you're still interested!