Before the invention of birthdays, children never aged, landfills overflowed with unused cakes, and wishes could only be made by blowing out forest fires. Commemorate your offspring's aging with today’s Groupon to Long Island Sports Complex. Choose between the following options:

• For $190, you get a sports party for up to 15 children (a $385 value). A $15-per-child fee applies to additional party members.
• For $240, you get an inflatable party for up to 15 children (a $485 value). A $15-per-child fee also applies to additional party members in this option.

Amid its 25,000 square feet of climate-controlled indoor turf, Long Island Sports Complex treats up to 15 birthday celebrants to one hour of motion-based merriment, followed by a half-hour of pizza, cake, drinks, and party goods. The facility takes care of all the food, decorations and invitations, so parents can spend more time knitting the perfect birthday gift or reanimating it during an electrical storm. Sports-party revelers get to release excess energy with their choice of soccer, baseball, softball, football, or lacrosse without the outdoor inconveniences of grass stains or slingshotted acorns from territorial squirrels. Two to four sport-savvy supervisors will be on hand to make sure that everyone has a safe time.

For a more gravity-defying gathering, the inflatable party gives youngsters an hour of boing-boingery inside three inflatable fortresses of fun, complete with slides, obstacle courses, and a full-court basketball area. With no sharp edges and constant pillowy protection, spills, falls and faceplants will result in delighted giggles instead of expensive reconstructive surgery. Like its sporting sibling, the inflatable party includes pizza, cake, drinks, decoratives, and invitations.