Diner City is an addictive flash based game where you try to build up a restaurant faster than a computer controlled opponent.
Here I have put together a few notes based on beating all five levels of the game.
Tutorial level: easy enough, no hints required.
Level one: early on, place an ice cream stand in a position where customers leaving your and your opponent’s restaurant will file past it. This will give you additional cash to upgrade your restaurant quicker.
Level two: acquire all upgrades on the top level that increase your revenue per customer. Then get the delivery vehicle. At this point, you should be earning enough to buy all the remaining upgrades from the top row that increase seats. You should beat the computer by ~10% using this method.
Level three: as soon as possible, place a newspaper stand or ice-cream stand outside the central restaurant. This will give you the additional funds to buy upgrades from the top row. As soon as possible, buy the second restaurant (you should be able to do this about day 13) and then buy the third restaurant. Then use the funds accrued to buy all the remaining upgrades for your original restaurant. This should lead to a quick defeat of your opponent by ~12%.
Level four: this is a tricky level if you do not approach it in the right way. Only buy the upgrades from the top row that increase revenue per customer. As early as possible, buy the second restaurant (usually at day 15) then as soon as possible buy the third restaurant (usually at day 17). This prevents your opponent acquiring a second restaurant which limits his revenue opportunities. Next, get the delivery vehicles for all three restaurants and use all remaining funding to upgrade the original restaurant with the biggest upgrades you can afford. Using this method, it is easy to beat your opponent by ~25%