I really like this, but there is room for improvement.
First, some extra hand sprites could be nice. Instead of nothing happening or the gun straight up disappearing in some cases, it would be nice to have custom hand sprites for reloading, being hurt, beating a level/boss, etc. Also, a bit more polish could be used - for example, there isn't a water filter for the hand underwater. Additionally, maybe a setting for aim assist could be added for poor aimers or people using a controller. Overall, this is a useful addon I use every time I play SRB2, but it needs a bit more work.