Use those pool noodles indoors too!
Pool noodles - as many as you'd like
One or several marbles
A small ladder, step stool, or whatever else you might want to use to gain some height
Cut pool noodles in half down the middle.
Tape the end of each noodle-half to the next noodle-half, making sure the inner channel is facing upward or inward (this may take some adjusting).
Wind the noodles around something tall for elevation.
Send a marble flying down the channel like it's a waterslide by placing the marble in the topmost part of the noodle chain.
Note: if your marble flies out of the channel before it reaches the bottom, try moving the position of the noodles and re-taping them in place.
Source: Inner Child Fun