Most Heartlake City sets list suggested ages from "4 Years and Up" through "9 Years and Up," covering preschool-aged children up to older kids.
Sets commonly include multiple minidolls — typically between 2 and 6 — and many also include animal figures such as dogs, bunnies, cats, and occasionally a gecko.
Built sizes vary by set: small vehicle-style models are about 5 in. (13 cm) high, many mid-size playsets measure over 10.5 in. high, and the largest multi-level builds can exceed 22.91 in. high.
Each set lists a suggested age, and many provide guided building support through the LEGO Builder app — including zoom/rotate 3D instructions, progress tracking, and Build Together features — to help builders with varying skill levels.
Listed Heartlake City sets indicate "Battery: No Battery Used," so they do not require batteries for play.
They commonly list developmental focus areas such as gross motor skills, fine motor skills, creativity, sensory development, and creative thinking.