It was 2015 when I first saw the developer of the game Let Them Come ($1.99) describe what his game would be about in our Upcoming Games forum, and I’ve been keeping an eye on the game’s development ever since because the idea at its core was pretty smart and its visuals retro in a good way. After a long journey that took a detour to the lands of Steam, Let Them Come has finally hit the App Store, and I’m glad to say that it lives up to my expectations in terms of gameplay. At least so far; I haven’t been able to get too deep into the game because I keep getting this weird crash that ruins my runs and has me start all over again. That crashing issue aside, Let Them Come appears to flesh out its simple concept very well.

What is that simple concept? In Let Them Come, you play the last survivor of a mission gone sour; you are the last survivor of a group of soldiers dispatched to take out an alien threat aboard a spaceship, and you’ve decided that if you’re going to go down, you will take as many of those alien creatures with you on the way. So, you set up your huge machine gun at one end of a dark corridor and wait for them to come. And boy do they come in waves.

You aim your machine gun using a slider on the left side of the screen and shoot by tapping (or holding) the various buttons on the right side of the screen. You can bring along two types of ammo, two secondary weapons, and four passive upgrades on each run, so there’s variety in how you approach each attempt. Each run gives you coins that you then use to buy or upgrade your equipment. You can grab incendiary, explosive, or other kinds of ammunition, grenades, molotov cocktails, knives, shields, chainsaws (for when it gets too close and personal), even dark matter bullets and many other interesting items.

Let Them Come plays a lot with darkness and light, with the edges of the corridor bathed in darkness that only your bullets and various other items can dispel. There’s definitely an Alien vibe in the way these creatures pop out of pitch black walls and jump on you. Speaking of jumping on you, Let Them Come often becomes very personal as little creatures jump on top of your head and you have to use your knives and chainsaws to take them out.

Let Them Come offers three ways to play (at least as far as I can see since the crashing has been hindering my progress). The one is a Campaign, which is all about clearing out levels of waves of enemies and trying to manage your upgrades as best you can. The Rampage Challenge has you competing for the best score on the online leaderboards, and in this mode you have 3000 coins to buy items with and then try and survive as long as possible and get the highest score. The last mode is a Boss Challenge one, but you have to clear Campaign levels to get to, which I haven’t been able to given the constant crashes.

Let Them Come is a lot of fun to play so far, and the variety of enemies (some of which explode on impact or throw projectiles at you) along with the various weapons you can use point to plenty of replayability. The game isn’t optimized for iPhone X, though, which is disappointing given how long this game has been in development. And the constant crashes I get have definitely dampened my enjoyment somewhat. Still, I’m pretty sure the crashing will be remedied soon, and even with those, I’ve still had fun playing it.

Let Them Come also has this fun feature where you can make your own mixtape and get the soundtrack the way you want it. It’s a smart idea given the important role sound and music can play in a game that relies heavily on evoking the action and atmosphere of horror movies like Alien. The game is $1.99 with no IAPs, so a good deal for those who don’t like free-to-play games. Head over to our forums for more impressions on Let Them Come.

UPDATE: A patch has gone out that appears to have improved most if not all of the game’s issues.