One guest at the party uses a wheelchair, and the game list you already wrote has musical chairs, a relay race, and a circle game played on the living room floor. The fix is not a modified rule for that guest. It is moving the play up onto a table and setting every target where a seated player can reach it, which changes nothing about the game for anyone else.
What actually has to change about a party game?
Three measurements: the height of the play surface, where the targets sit, and how far away you set the throwing line. Use a table at 28 to 34 inches with open knee space, put targets between a seated player’s elbow and shoulder, and mark one throwing line six to eight feet out for the whole group. Party Games for Limited Mobility covers the same ground for casts and balance limits, and Mobility Friendly Party Games and Setup has the room setup in more detail.
How do I set distances so a seated player isn’t at a disadvantage?
Measure from a seated position and use that number for everybody. A throwing line set for a standing adult puts a seated thrower at a real disadvantage in shoulder angle and power, but a line set at six feet is comfortable from any position. The same logic applies to how wide you spread a card grid or how far apart you set buckets. Party Games Guests Can Play at the Dinner Table is built entirely around this constraint already.
What do I do about tag games and floor circles?
Drop the tag games and lift the circles onto chairs or a table. Tag, freeze tag, and musical chairs are scored on floor-level speed, and there is no version of them that includes a wheelchair user as a genuine competitor. A circle game moves easily: put everyone in chairs at matching height so sightlines and passing distances stay even. Party Games With No Elimination and Cooperative Party Games With One Shared Goal both hold formats that never had a speed component to begin with.
What should I check before the day of the party?
Walk the route from the parking spot to the play table and look for the things that stop a chair: a single step at a doorway, a threshold strip, a hallway narrowed by a shoe rack, a bathroom door under 32 inches. Wheelchair Accessible Birthday Venue Checklist covers the venue side in full, and Party Games and Question Packs has the rest of the game inventory once the access questions are settled.