To do/see

Malta can offer the most you want to see/do. Well maybe not skiing and ice hockey, although in periods there is a small ring to go on in Paceville.
In Sliema, there are many places to swim from the cliff, mostly on the sea side. There are also around Malta numerous sandy beaches, mainly in the north of Malta. If you have a car you can seek out bays/beashes where one can go to be undisturbed. The water is clear and clean and there are a lot of small fish, a popular alternative is to dive and catch octopi. It's nice water to dive and snorkel in and there are several clubs offering dive training/diving trips.
If you want to be active, there are several options including hiking, golf, water polo, yoga in group or private personal trainer in what you want, bowling and more.
Paceville, Malta's party mecca, and there are a variety of nightclubs and bars. If you want something little quieter, there is a wide selection of restaurantes and pubs. There are also casinos if you want to play and a racetrack. Throughout the year there are festivals but mostly during June to September.
There are several museums on the island, largely for most interests. Many are focused on chivalry and World War II.
Excavations, as Hal Safilieni Hypogeum in Paola, where you can experience an under ground burial site is one of the world's most remarkable archaeological site. If you want to see this, it is good if you have pre-booked, preferably several months before. If you are luckey you can get a residual place the same day. There is much to see about World War II, the Church in Mosta which was bombed or why not visit one of shelters that people hid during the war, the largest is available in Mellieha. Shelters were dug out by hand and  Melliha is 500 m long tunnel with a few small rooms that families or important people got permission to dig. Each person had about one square meter available and there were several 100 people who lived there at the time. The lighting consisted of oil lamp so you can imagine how the air was domn there. A little smaler shelter are in Mgarr. There are about 370 churches in Malta, which are mostly free to visit. In Valetta, there is the opportunity to see a film about the hisory of Malta for 45 minutes, which I highly recommend.
For the kids
Playmobil Funpark, Popeye Village and Water Park are some of the attractions for the kids.
There are various parks that offer contact with birds and an aquarium. Places worth visiting are the Mosta with its church, Palazzo Parisio, Naxxar, with its beautiful garden. Marsaxlokk whish is the most beautiful an authentic fishing village in Malta, on Sunday morningsthere is the fish market. Blue Grotto where you can swim and take a boat trip and experience a wonderfulle clear, blue water. A trip to Comino and swim in the Blue Lagon. The swimming area is very famos so prepare yourself for congestion, but it is an experience to have been there. It also offers cruises, longer and shorter, around the harbor and to Gozo for example. Medina, the quiet town, was Malta's first capital, and of course a visit to Valetta, present capital, is in place. There are so many other places that are beautiful and interesting here in Malta so just to explore and experience.
To stroll on the promenade and just enjoy life is not completely wrong.