## 1 Introduction  
Children with Developmental Coordination Disorder (DCD) have difficulty with fine and/or gross motor coordination [1; 2]. Their clumsiness may cause difficulties in performing activities of daily living, e.g., dressing up and eating with utensils. Consequently, they tend to limit their participation in physical activities in early childhood and beyond [3]. These motor deficiencies may have mental, behavioral, and social consequences, affecting the quality of life of the child [4; 5; 6]. It has been recently suggested that it would be useful to understand DCD as a deficit in the perception-action relationship, in the context of the demands of the task, and the understanding of the child of his or her own action capabilities [7]. This view emphasizes the need for a comprehensive evaluation method of the difficulties faced by the child. Current common tools for diagnosis include questionnaires filled out by parents, e.g., the Developmental Coordination Disorder Questionnaire (DCDQ), or by teachers, e.g., the motor skill checklist [8]. Actual physical evaluation of the child may be performed using the Movement Assessment Battery for Children (MABC). The MABC is a norm-referenced assessment used to determine the presence of DCD by means of three subsections of manual dexterity, ball manipulation skills, and static and dynamic balance [9; 10]. A strong correlation was found between the motor skill checklist and the MABC [8]. As technology evolves, more accurate and user-engaging tools are proposed to evaluate and treat children with motor difficulties. Non-immersive Virtual Reality (VR) systems have been used to examine the quality of motor patterns of children with DCD [11], and also as an intervention tool for children with DCD [12; 13; 14; 15], as well as other populations, e.g., children with Cerebral Palsy [16]. Recently, [PERSON] et al. [17] found that 10-12-year-old children with DCD had a slower hand path speed, greater wrist extension, and greater elbow flexion than Typically-Developed (TD) children, while playing VR games. It was suggested by the authors that the deficiency in feedback processes in children with DCD may be aided through the feedback mechanisms that VR systems offer, e.g., cognitive feedback of the score, as well as auditory feedback and visual feedback. However, this interesting finding has not been explored in younger children with DCD. An earlier evaluation of the condition of the child may enable earlier intervention tailored to the child's needs. Another benefit of VR systems is that they might allow for the computerized recording of kinematics and kinetics data of the player while engaged in the game activity, so that using expensive, stationary motion capture systems and taping markers to track the child's hand movement may not be required. For example, it has been shown that the Wii balance board is a reliable assessment device for recording the movement of the Center of Pressure (COP), as a mean for evaluating balance disorders [18]. The simplicity and availability of inexpensive commercialized VR systems may prove to be an important tool for the early evaluation of different aspects of motor awkwardness in young children with DCD. In this study, we concentrated on a young population of children and incorporated a simple mobile VR system, designed for young children. It acquires kinematic data without the need for an external measurement device. We aimed to (a) compare the performance between TD children and children with DCD in the VR game, and (b) explore the correlations between the performance in the VR game and the grades in sub-categories of the MABC in children with DCD. The performance in the VR game was quantified using the game score, the ranges and path length of the COP movement, and the path lengths of each hand. While we hypothesized that the manual dexterity and visual-motor coordination scores would correlate with the VR parameters (game score and hand path length), we did not expect the game to detect balance impairment.