When the UFE loses contact with the Hammerhead, a spaceship sent to check out a distress call on a distant planet, guess who is sent to investigate? Yes, you, space marine! So lock and load — chances are good you will be facing more than a few Hostile Spawn.
Hostile Spawn does not carve a new genre. The whole "send a military-type out to fight hostile alien creatures from another world" bit has been done a few times before (Aliens, Starship Troopers), but, really, does that matter so much? Taken from a top-down view, you control the marine with directional keys (typically the [WASD] keys) and manage firepower with the mouse. Recently, the addictive Robokill 2 set the benchmark for this kind of game, so how does Hostile Spawn fare? It's worth comparing the two, even though fans of the one will enjoy the other, they are quite different games.
In Robokill, you eradicate aliens for the sake of space colonial peace room by room. In Hostile spawn, you explore the entire base. It is much more objective-driven: find a computer, blow up a reactor, etc. After accomplishing the level objectives, you make your way back to the elevator and a floor deeper into the infestation (in the event of taking out a reactor, you run). Initially the ship, which serves more as a prelude, has to be cleared, then you hit the planet and dash to the facilities. It's no surprise that those places are also overrun and need some bug removal. To do the job you use weapons and ammo you find in the levels, as opposed to Robokill's shop system. There is also no upgrading, just ranks you achieve as you stack up kill points.
Analysis: Hostile Spawn's pros outweigh its cons, but it's not an outright win. This is a fun game, no doubt about it, and a bit more fleshed-out than most of its peers. Visually it stands out, thanks to its use of Java to give it a bit more power (though Flash Alchemy could achieve the same results) and there is something about the old-school aesthetics, such as an armory that includes shotguns, railguns and rocket launchers, that makes this an engaging experience. It's not very easy, either, because there aren't any health packs lying around (despite their appearance in the help menu) and dying means you restart the level, regardless of the objectives you had achieved.
On the downside, you pretty much do the same thing over and over again. With the exception of the planet surface, all the maps feel the same, the monotony only broken by increasing signs of alien stuff growing against walls and minor variations in the facility decor. Fortunately the loaded atmosphere keeps you far too busy peeking around corners and trying to stay alive to really bother writing a pithy letter to Home Decor Monthly — but some more variation across the ten levels would have been nice. Once again we can compare to Robokill, which also changed its decor about as often as a government office, but that game was not focused on exploration. Hostile Spawn is, which is perhaps why it also has very few enemy variations. You need to go through quite a few levels before you see something other than the monsters that keep attacking you. As with the decor survival is more important than cataloging the invaders, but when both are static it can get a bit samey.
The game does a good job using dark areas and hidden corridors to keep our marine on his toes, while distant screams from the aliens alert you of their approach. The sound design is great and the weapons in particular are very satisfying, not to mention the eerie ambient soundtrack that fades in and out. If a final comparison has to be made, The Robokill series is firmly rooted in arcade traditions, whereas Hostile Spawn is a slightly more cerebral horror experience. This ends up being its vindication: you forgive its repetition and lackluster enemy roster because it blankets itself in a nice atmosphere.
Ultimately Hostile Spawn is a safe game: it has a lot of good ideas that it executes very well, but it keeps innovation trim and feels a bit shallow. That said, it is well worth playing through once and if the developers add a bit more spice to hint at what the expansion can deliver, I'd more tempted to consider the recently-added commercial expansion.