It just feels like any other bigger western overpriced capital (like London for example). I wasn't really impressed with it. It's fine for what it is, but once you start including the prices for spending time here it really drops down. Whole city seems very artificial, feels like some demo map of some city building video game (one which looks good, but will never happen when you play). Loads of pointless shopping malls. You would think it should be some kind of futuristic city (with it being so expensive), but there is a lot of things which you can find better done even in some eastern Europe cities. In the city center everything seams fancier (of course and more expensive), but once you go to the other districts you can see a different side of the city. In any case I was not impressed and probably if I was ever back it would only be for a transit to a different country. Whole city/country just feels... closest word I can come up with is "castrated."
The currency is Singaporean dollar (SGD). The rate is about 1.52 SGD for 1 EUR, 20 SGD for about 13.16 €, 50 SGD for about 33 €. You can pay with card in most places, but some still require cash. Using ATM might hit you with large fees, like 5 € for just taking couple hundred of SGD.
This information will be different depending on your nationality and even if it's the same it might be outdated, check to be sure. I like to check this Wikipedia page which lists all requirements for Lithuanians and VisaHQ to be sure. You can also Google using your native language which might provide some useful articles.
Not required for 30/90 days stay.
You can get a local SIM card at the airport. 3 GB card costs about 25 € (valid for a month). You can get much better deals if you're staying for less than a week.
There is a lot of places to eat with many choices. A lot of them crowded open air spaces.
Singapore Botanic Gardens is a large park, actually it feels more like multiple parks combined into a single one. Good to just walk around in all the nature. Can be really humid and shower yourself in bug spray as mosquitoes are hungry. It also contains orchid garden for which you have to pay and unless you really like orchards it's just not worth it.
Traffic / Walking
Walking around is simple, big side walks, safe crossing of the streets. One of the issues is the weather, it's humid and hot and maybe raining also (which does not take long) so try to stay in the shade and even then it might not be comfortable for some people. Always have water with you.
The city feels kind of dystopian present, with all the warning sings along the lines of "Follow the rules or we will make you disappear", but at the same time when you look at the dirty streets it makes you doubt if actually anyone cares about them. It was also very surprising how many smokers there are.
Other options for traveling is public transport, just get an ezcard and top it up. Can be sometimes annoying to wait for a bus as Google Maps might be giving one information and you just keep waiting. You would also expect that buses would have screens with all the info, and bus stops will have screens about next buses and time until them, but you can forget about that. MRTs on the other hand are easy to use and understand (they just often make me sick riding them).
You can take taxi from the airport. It will cost about 16 € (10% of which is paying with card fee).
Challenger store near Bugis Junction is a good choice if you want to get some electronics. There are two shops in the same building (one downstairs and one upstairs). Have your passport with you and get GST refund documents (which you fill in at airport before leaving).
Entertainment / Visit
Chinatown Heritage Centre a well done museum which allows you to see and feel how life looked before for immigrants. Top floors are not that interesting (and you might be tired by that time), but first two floors are education and well done.
(from external source) Usually sunny. Rains almost daily - sudden, heavy showers for less than an hour. Most rain during November to January. Forest fires between May and October. Temperature averages around 32C during day, 25C during night.
I was visiting end of May, beginning of June. Weather was kind of unpredictable, you might get rain, you might get sun, you might get cloudy. It reminded me of Kuala Lumpur weather (which I did not like).
For other locations in the world see intro article.