This is a fairly sturdy high chair. It is made up of metal poles that have the little pins to lock everything into place. I was able to put it together without even looking at the directions, but instructions are provided as well. The chair portion is one solid piece. The only assembly needed is for the legs. The cushion is not overly padded, but it is of good quality and can be easily wiped down or cleaned. The tray is removable and easily slides on and off with a locking feature on the undersides. The tray has a fold down plastic piece that goes between the baby's legs for added stability in the event of sliding out, but the chair does also have seat belt straps to fasten the baby in. The arm rest pieces are a little wobbly but once the tray is fastened, it is sturdy. This high chair does fold up by pressing on the button at the foot rest, but it does not fold completely flat (without the tray attached) because the seat portion is all one piece and does not fold. The plate actually locks into the tray with little ridges by sliding it clockwise or counter clockwise. You would think that the plate would be positioned with the largest compartment closed to the front, but it does not because of the clip position on the plate itself. There is also a mesh pocket on the back to hold bibs, etc. The aqua play mat is just a play mat. It blows up with a portion air and a portion that you can put water in so the fish float. This play mat does not attach to the high chair and can be used elsewhere as well. All-in-all, this is a nice high chair that should function to your needs.