The American Psychiatric Association has identified Internet gaming disorder (IGD) as a potential psychiatric disorder. Questionnaires are the main method to classify high-risk IGD (HIGD) and low-risk IGD (LIGD). However, the results obtained using questionnaires might be affected due to several factors. Flow can measure a person's state of concentration and cardiovascular signals can reflect the autonomic responses of a person. We propose to observe the cardiovascular responses and flow scores from the flow short scale of the HIGD and LIGD groups to assist questionnaires in IGD risk assessment. The preliminary study recruited 18 gamers from colleges. Games with the easy and hard levels were set to arouse desire for playing. The result showed that the flow scores of five HIGD participants were significantly lower compared with that of 13 LIGD participants. The stroke volume (SV) of the LIGD group during baseline (67.06 ± 11.61) was significantly greater that of (p < 0.05) while playing the easy game (64.08 ± 10.37) and playing the hard game (63.70 ± 9.89). For the LIGD group, the cardiac output (CO) during baseline (5.28 ± 0.97) was significantly greater (p < 0.01) than that of recovery (5.03 ± 0.83), and while playing the easy game (5.34 ± 0.98) it was significantly more than that during recovery (p < 0.05). For the HIGD group, a significant difference in the heart rate, SV, and CO was not observed. The changes in cardiovascular responses of the LIGD group are greater than that of the HIGD group. Gamers with LIGD might have a higher susceptibility to the negative effect of playing video games, but gamers with HIGD might not. The finding of this study might help psychologists to estimate the IGD risk.Clinical Relevance- This study investigated the differences in the score of flow short scale, self-assessment manikin, challenge/skill, emotional questionnaire, and the changes in the cardiovascular responses between the HIGD and LIGD groups.