Tips:
-Always refill fuel and gifts before upgrading, an upgrade increases the refill price, if you end up unable to pay it, you have to start all over because you can't advance with 0 fuel or gifts and can't use your remaining money to partially refill anything
-How to definitely win before dawn (first medal): ignore everything and only refill and upgrade fuel. A gift costs 200$, hitting a house is worth 100$, a kid 20$, so distributing gifts costs more money than it pays.
By only refilling and upgrading fuel you will win at around 00:40. It's impossible to win before midnight, I tried.
-How to run out of time (2nd medal) without getting stuck on the no-refill problem:
Waste most of your gifts constantly, but not TOO fast or you don't gain enough money from traveling to refill fuel and gifts. Keep wasting them to return to the shop constantly until you lose, always keep about 50k$ as backup for refills.
Spoiler for secret medal: upgrade your attraction a lot. I leveled it to 15 on my last run and then got it after refreshing the page again. Maybe it already unlocks before that, but it doesn't say when exactly.
Beware that the game gets a bit laggy during the 4th and 5th area, that, the refill-reset problem and the overall weird controls and plain graphics are the reason for my rather low score. But it's an old game so I guess it deserves at least 50% score for what it is. As part of a game-jam there must've also been a time limit to finish it, so it's not that bad.