Play with friends in paintball. Both in Moscow and in the suburbs, a lot of paintball clubs where you can have a cheap and great way to relax great company. Visit, for example, such complexes as "Revolt-Mitino", "Revolt-Ruble" or indoor paintball field arena.
Go with friends or family to the water Park. You will have the most joyous birthday, as you can imagine. Slide frolic in the pool. In a special area to sit and drink light cocktails for the health of the birthday. It's not the most expensive option for the celebration in Moscow. Choose among the many options is the closest water Park "kVA-KVA Park" (Yaroslavl), "Fantasy" (metro station "Marino"), "Kimberley Land" ("Sevastopol"), "Soyuz" (39 km Shchelkovo highway), Likhobory ("Petrovsko-Razumovsky"), "Marina Klab" (the Leningrad highway), "Scarlet Sails" ("Shchukinsky"), "Prime Sports" ("University").
If your birthday falls on the cold season, spend it at the rink. In principle, and for summer you can use this option, but will have to look for a closed room. It is a cheap pleasure, but you will get a lot of romantic feelings, if you visit the rink with the second half. To skate go to the Park of culture. Bitter, Kolomenskoye, on the Patriarchal ponds, Sokolniki, Hermitage garden, etc. Or invite your friends to kinematic where you can enjoy not only skating, but also watching movies or videos.
Birthday go to the ski slopes. To set, for example, in Krylatskoye, Novoperedelkino, on the Sparrow hills, etc. Even if you do not possess enough ability to go skiing or snowboarding, do not worry. Experienced coaches that are on roads will help you to quickly settle on the mountain slopes.