Levels where you can use the IBT to glitch-complete the level:
Guard Post One - Go to where green key is, do IBT in corner, duck
First Dome of Darkness - Go to right end of stage, IBT, duck
Bloogdome - Here, you don't actually glitch to directly complete the level. You just use the IBT and duck to get through some walls. Go to corner of starting platform, IBT, duck, fall, go to closest UPPER corner on right, IBT, duck, get to exit.
Bloogton Manufacturing - Pogo to first ledge on right where red key is, corner IBT, duck
Bloogton Towers - Go to arrow on right, IBT, land on right side of top floor, go to right corner, turn around, IBT, duck
Bloogfoods Inc. - It is very complicated, so I have posted a picture.
Guard Post Two - Another "glitch through walls" level. Go through the middle entrance, fall, IBT on closest UPPER corner to right, duck, IBT to get to ledge on right, fall through hole, get to locked exit, IBT in corner, move right, get to exit.
Bloogville - The simplest one to IBT-complete. Just IBT, duck, move right until level is complete.
Bloog ASA - Get to locked yellow key door, IBT, duck, move right until level completes.
Guard Post Three - Same as Bloogville.
Bloogbae Rec District - Get to electric wall thingy, IBT, land on top ledge, go to door on left, exit.
Bloogwaters Crossing and the secret levels cannot be completed any faster by IBT.
Bloog Control Center can be completed with IBT, but it will gltich the game to where it can't be beaten.