Growing up in Peoria, I've spent quite some time partaking in a wide array of activities at Thunderbird Paseo Park which I refer to as simply "the canal." Everything from family bike rides to ice blocking to soccer practice has taken place at this park.
The whole park stretches about five miles through more than one municipal area. I really enjoy the bike/pedestrian trail because it is a good way to safely avoid major intersections on long bike rides. This path also boasts a workout course with pull up bars and sit up stations at half mile intervals.
As far as ice blocking goes, I would not use Paseo park. The grass is much to dry to provide the slippery surface necessary for a good slide. The golf course on 40th Street and Cactus is much better.
I haven't had a chance to check out the new disc golf course yet, but my brothers and dad say that it is awesome. I'm really excited to throw some disc here when I have a little more time to hone my skills (which are close to none).
This is a great park during the day; however, unless you are armed or have a death wish stay away from Paseo Park at night. I have seen some pretty odd things on late night bike rides, and homeless people sleep under the overpasses.