K.Z.
You should check out "Out Of This World!" It's a totally sweet place to play, great for any age AND parents love it too! They have 15,000 sq ft of indoor play area with a tall climbing structure that has 4 slides, inflatables to jump on, plasma cars to ride, a reading and crawl area (mostly for babies), slides just for little ones (under 2), and a pretend area with house/kitchen and grocery shopping with play food. They also have a pizza parlor (limited menu and a little pricey but the food is GOOD).
http://www.outofthisworld.net/
Papa's Pizza has an indoor play area. Free to play but it's nice to buy something off the menu to support the business.
http://www.papaspizza.net/Beaverton.aspx
Pump It Up is awesome! Lots of inflatables to jump on, it's great for wearing the kids out. The Junior locaton at Bethany/Cornell even has special times for only kids 3 and under and special visits from characters like Elmo and Dora.
http://www.pumpitupparty.com/or/beaverton/home-p1q6.htm
Top Notch (by the Hillsboro Costco) has had play time for little ones, but I'm not sure if they still do. Check their calendar or call and ask about the preschool playtime. They have several trampolines and a very large tunnel maze type thing (air blows it up and kids run around inside it).
http://www.topnotchttc.com/Home.html
Each of these places is around $5 except Papa's which is free. We frequent OOTW the most, but I like them all. Easy on the budget and a variety of different activities. I like Me Too the least because you have to lock your kids inside a little room and you can't play with them! It is also the smallest. I am not familiar with Munchkin Playland!
Your child is still young, but all of these are appropriate places for him if he can walk, run, and jump! And if not, these places can help him build those skills! (My friend had a late walker and her physical therapist recommended Pump It Up and before long, she was walking like a pro!)
There is also Safari Sam's in Sherwood, but that seems more geared towards older kids (mini golf, climbing structures). I just wanted to post their info in case other moms are out there looking at this post for ideas of fun places to play!!
http://www.jungleoffun.com/
Have fun!!! ~K.
(You should also check out http://www.passitonsales.com We have an event coming up in April and often have great coupons for places like these in our shopper Goody Bags!)