I admire how Adam Sandler has developed his potential as a performer during last three decades. While his entire career has been riddled with a heap of disposable comedy films such as “The Waterboy” (1998) and “Jack and Jill” (2011), he also has often demonstrated the more serious sides of his acting talent in a number of notable films such as “Punch-Drunk Love” (2002) and “Uncut Gems” (2019), and I have been fascinated with how his screen persona has got gradually matured via these better movies.

In case of Netflix film “Spaceman”, Sandler is willing to push himself further as dialing down himself much more than before, but his commendable efforts here in this movie are not unfortunately supported enough to my disappointment. As an isolated astronaut in the middle of the demanding space mission, Sandler is often effective in his subdued illustration of aching conflict and loneliness, but the movie often loses its focus and momentum for not being totally as committed as its lead actor, and it also fails to distinguish itself from “Ad Astra” (2019) and many other similar science fiction drama films out there.

At the beginning, the screenplay by Colby Day, which is based on Jaroslav Kalfař’s 2017 novel “Spaceman of Bohemia”, slowly establishes what Sandler’s astronaut hero, a Czech dude named Jakub Procházka, has been going through during last several months. A few years ago, a mysterious interstellar cloud suddenly appeared near the solar system to the surprise of everyone on the Earth, and we gather that a number of different nations embarked on each own space mission for exploring this inexplicable interstellar cloud. In the end, Czech’s spaceship somehow became the first one to reach to the interstellar cloud (South Korea happens to be the second one, by the way), and Jakub will soon get the honor alone by himself because he happens to be the only crew member of the Czech spaceship.

However, it is evident to us that Jakub has been struggling with the growing loneliness inside his mind. While he certainly tries to focus on his mission as usual, he comes to miss his wife Lenka (Carey Mulligan) more than before, so he becomes more dependent on his occasional interspace communication with his wife, but his wife turns out to get more tired of how he has often been absent in their married life. She has been pregnant during last several months, but her husband seems to be less interested in their baby, and she eventually decides that enough is enough.

When Lenka is about to tell her husband about her decision to end her marriage, everyone at the mission control becomes quite concerned for a good reason. Knowing well about Jakub’s emotional toil, Commissioner Tuma (Isabella Rossellini) decides to block the communication line between Lenka and Jakub for a while at least, but that only comes to exacerbates Jakub’s loneliness, and he becomes all the more stressed as the spaceship is having a number of small and big problems.

And then something really weird happens to Jakub. He comes across a big spider alien voiced by Paul Dano, and he is certainly thrown into panic while not so sure about whether this strange entity is actually real or not. No matter how much he tries, the spider, who is eventually named “Hanuš” by Jakub, does not go away at all, and Jakub has no choice but to accept his unexpected companion after discerning that Hanuš comes in for, uh, peace.

Because Hanuš happens to have a telepathic ability, it soon comes to look around the personal memories from Jakub’s life, and the movie naturally comes into the territory of “The Tree of Life” (2011) and “Ad Astra”. As cinematographer Jakob Ihre’s camera presents a number of different moments in Jakub’s life via deliberately distorted images, the movie becomes more introspective along its astronaut hero, and this introspective mood is accentuated further by the score by Max Richter, who incidentally also worked in “Ad Astra”.

However, Day’s screenplay also attempts to handle Renka’s growing personal conflict on the Earth, and that causes the main problem of the film. As alternating between Jakub’s main narrative and Renka’s subplot too frequently, the screenplay fails to develop both of these two main characters enough to hold our attention, and the movie consequently trudges from one expected narrative point to another without much dramatic weight. In the end, we do not care that much about whatever will happen between Jakub and Renka, and the same thing can be said about his strained relationship development with Hanuš, which is pretty predictable to the core even during the supposedly climactic part.

The movie also under-utilizes its several main cast members besides Sandler. While she is reliable as usual, Carey Mulligan does not have much to handle from the very beginning, and I must point out that she recently played a more interesting long-suffering spouse in another Netflix film “Maestro” (2023). Sounding as flat as HAL 9000 in “2001: A Space Odyssey”, Paul Dano manages to inject some personality into his alien character, and Isabella Rossellini and Lena Olin bring a little touch of class to their thankless supporting roles.

In conclusion, “Spaceman” is thankfully not a total bore as I feared, but it fails to bring anything fresh or distinctive to its genre territory. Director Johan Renck, who won an Emmy for HBO TV miniseries “Chernobyl”, and his crew and cast members do try a lot here, but the overall result is frequently middling on the whole, and I must confess that my mind kept going somewhere else during my viewing. At least, the movie shows that Sandler’s ongoing maturation as a compelling actor to watch, and I am sure that he will soon fly beyond it for whatever he will encounter in the future.