The performances by Dennis Quaid, Meg Ryan, and Martin Short remain the film's greatest strength. Short, in particular, works overtime to make his grocery store checker Jack Putter a manically funny creation. Jack is a hypochondriac who finally has a medical issue to be worried about. Military aviator Tuck Pendleton (Quaid) is part of a top secret experiment in which he will be shrunken to the size of a speck of dust and injected into the bloodstream of a lab rabbit.
Before that can happen, however, a spy (Fiona Lewis) attempts to hijack the experiment and steal the minuscule Pendleton. Quick-thinking experiment admin Wexler (John Hora) manages to flee the scene with Pendleton floating around in a tiny vessel within a syringe. Following a chase that finds him confronted by bad guys, Wexler injects Pendleton into the nearest bystander. That happens to be Jack Putter. So begins an initially funny caper in which the hapless Jack starts experiencing weird, sometimes painful sensations and hearing a voice (Pendleton's) in his head. It's a fun premise, just like the old Disneyland ride Adventure Thru Inner Space (which closed 30 years ago, dating myself here big time).
So the "good guys" wants the new miniaturization technology for scientific purposes, while the "bad guys" (headed up by Robert Picardo's Cowboy and Vernon Wells' Mr. Igoe) want it for nefarious reasons. Meanwhile, there's a rocky romance that needs mending between Pendleton and Lydia (Ryan). As the plot careens forward, it thickens into a mess of mostly action-oriented set pieces. The comedy that makes the first half of the film so winning dissipates rather quickly and abruptly.
Warner has brought Innerspace to Blu-ray with a nicely detailed and very clean transfer that preserves the grainy look of its mid-'80s era. Having not seen the film since the days of VHS, this was a wholly satisfactory upgrade. The audio is DTS-HD MA 5.1 and, while generally focused on the front channels, is very solid. The mix opens up a bit for the heaviest action-oriented scenes.
The sole extra here is an audio commentary track carried over from a previous DVD edition. The participants include: director Joe Dante, producer Michael Finnell, effects supervisor Dennis Muren, and cast members Kevin McCarthy and Robert Picardo.