oh wow.. yes now i see somebody asking for a save feature... so listen up dude or dudette. in my opinion nobody will give you contribution unless you add a save feature to your game. i only tip game developers after i have played the game and find i enjoy it greatly.
for example i order a meal at your hypothetical resturaunt, i ask for a to go box. you say TIP ME, then i will give you a to go box. otherwise you can just carry your food out in your hands! :D you wont see a dime from me or more than ten minutes of playtime without a save feature.
thanks, i tried to be nice XD.