These are some games that my 2-yr old daughter seems to enjoy, hopefully it will give you something to use! Since she loves books and is just tapping into her creative potential, I try to give each of her activities names based on books we've read or that sound fun. That way she likes them even more, and can ask for a specific activity if she wants to do it again. Also, we use basic props around the house, and have found that the non-toys are actually more fun than kid toys. Basic props include cardboard boxes, big blankets, cushions or pillows, laundry basket, etc.
Examples:
"Walking on the Moon" - put down pillows and floor cushions on the floor, and cover them with a big blanket. Then start walking on it saying, "I'm walking on the moon." Can expand to jumping, crawling, etc. My daughter had a blast asking for ring around the rosy on the moon!
"The Bear Went Over the Mountain" - We had read a cheap board book based on the familiar song. The next time our daughter started crawling on us, we started to sing the song. She got great delight, and now asks for it frequently. We don't have to do anything, she just crawls over us (we can be on the floor, sofa, etc.), and we sing The Bear Went Over the Mountain as she's climbing.
"Quicksand" - Our daughter came up with this game. One day I was sitting on the sofa with my legs resting on the coffee table. It was cold so I had a blanket over me. The Lucy began crawling on me, next thing I know she's falling between my legs into the blanket. It didn't take long for her to enjoy the sensation of falling into the sinking blanket. We started calling the game quicksand. And she loves both falling into the quicksand and also clamoring to get back out of it!
Blanket play in general: We have harwood floors, so one game we started was to drag our daughter across the floor on the blanket. Though this does make one tired after a short while. We also use blankets like they are parachutes, and spread them out on the floor, then wave it up and down. Lucy loves running across the blanket when it is moving, or lying underneath the blanket. We also turn her into a "burrito" and wrap her up in the blanket like a burrito.
Boxes and Laundry baskets: great things to climb into, to scoot around on the floor, etc.
Hide and Seek - we play this, but it works best if both my husband and I can do it with our daughter. That way one of us can hide with her, or help her find the one who is hiding.
Balloons, balls, bean bags, etc. If you are ok about things being thrown in the house, these are fun things to use as well. We have an assortment of balls in different sizes and shapes, and at any given time can easily engage in "bouncy ball" play. If bouncy balls are an issue, can use balloons or small bean bags and direct the throwing into a box or laundry basket, or against a blanket, etc.
Blowing bubbles inside! I have our daughter spread out a beach towel on the floor first. Not all of the bubbles land on the towel, but for the most part it catches them. Try giving your son the wand so that he can try catching the bubbles on the wand.
Or just put on music and dance to it! Give him some instruments (pot lid and wooden spoon, baby rattle, bell, etc.) that he can play along to the music.
Hopefully something in there will give you ideas that can work! Good luck!