Console games have a place but if you want to lower your childs stress level you may want to turn to a PC. Here you can get more appropriate and much more educational games. Face it, console games are for entertainment.
The computer is a tool not a toy. If your child has any diagnosis in the autism spectrum you will want them to learn to type to communicate. No console has a keyboard they can learn to express themselves with. The earlier they start the better they will be at it. Schools would never use a console as a teaching item.
Many childrens shows have websites and your child will find enjoyment from visiting them with your supervision. My child has Aspergers and loves puzzles. We find many easily printed colouring pages and mazes for off line enjoyment. If the level of frustration gets too high we can switch to something else fairly easy.
Also look for games that offer more open range for them to explore and do small tasks. Not FPS or RPG just they won’t understand them. Things with a fixed story or just idle combat won’t help them or you.
As an aside you should see some of the rollercoasters my kid has designed in Tycoon. Amazing for a 5 year old!