Just some suggestions;)
Its fun & well done... I liked the graphics and really enjoyed playing:)
As for suggestions-- it would be cool to choose which upgrades to get....
-Maybe you could choose to have more than one type of chair/tub/steam room/serenity/swimming area/etc)
- Or an assistant whose job is to clean up the tubs/steam area/etc
- Or a receptionist whose job is to collect the cash
- Or the ability to clean things before they get dirty (when there's a small lull in the game, instead of when they need to be done & everyone wants to get in them)
- Or the ability to advertise the spa for more customers... or to change the prices
- Or decorate the different spas