Quick Search:

Game Information
Release Date
Last Update
Orig PC Gender
Adult Themes
TF Themes

Version: 0.9.0

Version: 0.8.8

Version: 0.8.7

Invasive Species

Invasive Species is a CYOA story where you play as the monster. You make decisions on how you will proceed, find ways to become stronger, hunt humans to enslave and breed, and ultimately discover who you are and why you are on this world.

The story is currently incomplete. I will post updates as new parts get finished. My English is passable, but not great. Constructive feedback welcome as I try to improve my languages skills. I tried to incorporate both a present first person perspective at all times which I found grammatically challenging and a developing understanding of the world as you explore which I also found a difficult element to maintain through various branches of the story.


Alone and with no memory, you crash onto a planet.  You emerge from your organic ball of a ship and discover you're a tentacle monster.  You have no idea where you are or who you are, but you'll quickly learn you can get information from things you touch and you have the ability to affect them as well.  Vaguely you recall something of a "mission" or "purpose", but that seems lost to you.  Will you discover your true purpose?  Can you complete your mission?  Breed an army?

There are four primary story arcs, each with variations and branches (and ways to die).  Here's how to get started on each:


From your crash site, Seek Shelter at the tree, then Wander

From your crash site, Leave the Tree Alone, then go Left on the road

From your crash site, Seek Shelter, Wait out the Storm, Flee the humans, Open the door.  From that story arc there's a big split on whether you stay with Mira or leave her.

All paths will eventually lead you to some version of the ship and the paths narrow down quite a bit from there.  Unless you die first.  There's a lot of ways to do that.

Version 0.7.5 Uploaded:  Significant amount of sheer writing uploaded; starting the main end-game sequence (though not yet connected); I opened up the last town that had been previously cut off, some more transitional choices to switch to major story arcs, a lot of additional choices, bug fixes, typos.

Version 0.7.6 Uploaded: Added more content; the town of Bortin has more to do, more work on the final confrontation, though I am saving that for accessible when it is fully done; at which point the game will have it's final series of decisions and endings.

Version 0.7.7 Uploaded: Content, content, content!  Mostly in the new town; though more work on the ending too.  Still can't access the ending as there's parts of the ship I haven't finished, but it's getting there.  I'm also rescaling the planned size of the finished product and my expected completion date is at the end of October.

Version 0.7.8 Uploaded:  Thanks to a couple of people, including a big help from garyplume, a number of typos, grammatical mistakes, and other issues have been fixed.  Additionally, the apartment route is down to only one dead end.  Didn't get a chance to add much to the farm route, though a number of the other routes got small fixes or a few line changes.

Version 0.7.9 Uploaded: Some content update, a small amount of additional scenes.  We were unable to get as much done as usual this week.  Hoping to have a larger than normal upload for next weekend though.

Version 0.8.0 Uploaded: Large amount of new content including several actual ends to the game.  Not every path has an ending, but a few do.  Expect this to not be the final text for the last few sections and that there may be some scenes inserted in between in the weeks to come.  More content for Bortin was added and we rewrote a couple sections from older scenes to improve them.  This also marks the crossing of the 100k word threshold!

Version 0.8.1 Uploaded:  Small update, some corrections, tied up a number of plot lines in the Outskirts; a bit more to do and then I'll fill in the Downtown content and finish the diner arc.  After that it's just the ship to finish.

Version 0.8.2 Uploaded:  Content updates in a number of places, a couple of new endings added, more branches finally coming together.  There's still a lot of work to be done and we're now looking at mid to late November to get it all finished as we're adding some additional things.

Version 0.8.3 Uploaded:  Decent sized content update and some old scenes fixed.  All of the Outskirts *should* be done.  Along with the Apartments being done, that leaves only "Downtown" to write for Bortin plus whatever happens to the "Cosmic" people.  After that, it's just finishing up the ship scenes and adding a number of additional endings to tie this all together.  Enjoy!

Version 0.8.4 Uploaded: Additional content added, some older scenes rewritten or tweaked.  Spelling and grammar fixes.

Version 0.8.5 Uploaded: Fixed a couple of errors people sent us, finished the police station's paths, more work on town town.  Part of the Coffee shop plot can lead into Bortin.

Version 0.8.6 Uploaded:  More content for the plotlines that go through Bortin, only three loose ends there left then the rest for us to finish is on the ship.

Version 0.8.7 Uploaded:  Ship content added; most of the armory story arc is now in and eventually leads to the game end now.

Version 0.8.8 Uploaded: Endings are all in.  Ship content is done except for the Engine room route.  All other content is finished except for Bortin University, the Department Store, and the Office building.  We should have those done in the next few updates.

Version 0.9.0 Uploaded: More content, less dead ends, and some fixes for mistakes found.  Nearly done with the ship.  We're hoping to have this whole thing wrapped up in another few updates.

Latest Reviews - View All Reviews

Review by Raabbii

Version reviewed: 0.8.6 on 01/06/2018

I am not a big M2F guy so playing a monster who can dominate and convert women into Broodmother seems very good to me.

The writing is good and I really like the game, played until all the branches were at an end so I do recommend this game very much.
There's tons of variation even early on and choices can take you in wildly different directions

But In my opinion, I think the number of branches is so different it means the plot itself is very short, there are tons of roads but they all stop slowly. 
So I want to thank the dev for creating this and I do really appreciate it. But I do hope he will add a way to access all/most of the scenes after getting out of the Ship. 

Review by Shinchan

Version reviewed: 0.7.8 on 09/17/2017

Heyyy... That's pretty good! 

Review by garyplume

Version reviewed: 0.7.7 on 09/10/2017

What can I say? I have never much cared for Mind Control or Non-Consensual or even Choose Your Own Adventure, preferring to respect the agency of the love interest within the freedom of a text parser, but this story... I'm envious I didn't think of it myself, even though I have published a game where you play a dog romancing a woman. I'll admit that tentacle/monster pictures have occasionally been a turn-on (see Homealone_447's Caterpillar), but usually I can imagine a consent somewhere. I'm so shocked and ego-dystonic at how fun I found this MC/NC/CYOA story, that I feel I've been bewitched by the author's mind-controlling gases.

What fun to play the role of the monster sexing up a world full of fertile women, while trying to dodge the long arm of the law, and learn the mission. I love the varied fantasy settings of space ships, gritty sewer, divey diner, women's college, rural farm, urban apartment, etc. Also, the first person's retrograde amnesia is a good device to provide immersion, fresh perspective, and character development. There's a bit of a rut in the way the sex takes place and sometimes it feels like details start to blend into a formulaic blur, but for the most part it's quite hot. The author's efforts at varying the pacing and at least the environmental details of the sex are noticeable. Romance is reduced to a survival/hunting atmosphere which again is surprisingly appealing to me. Many of the NPCs are fleshed out with distinguishing details and there's even a MILF, but sometimes I craved a bit more: funny accent, distinguishing hairdo/birthmark/jewelry/tattoo, weird mannerisms, crazy/ditzy, incompetent/bad-ass/nerdy/self-righteous, sub-fertile/super-fertile, Goth/too-cool-for-school, old/chubby, even slightly ugly in the wrong light. I have also not been a fan of preg/bimbo, but it really works here.

The branches are full of long paragraphs of content. The addition of some quantifiable statistics made me want to replay all the branches to find all the content and the various stat boosters. Some branches loop back into other stories, further complicating the maximization game. I have never mapped out a CYOA game before, but now I have made an exception for this game. As the author says, there are about four main branches, each with about 4-6 named love interests, that tend to converge on a final common path. Thank you, ArmyofRobots, for opening my eyes to this combination of flavors and for some great fun.

Review by Dragon_ANGL

Version reviewed: 0.7.7 on 09/09/2017

Quite an interesting game. Playing as a transformative alien, while not being inherently transformed yourself save for offscreen purposes, is quite fun. Two major story arcs from what I can find out at the moment, being the initial path for which place gets infested, but thereafter it merges into a single path afterwards, which helps to cut down on the nigh-infinite branches that plague other ambitious works of this nature.


Also, I like how even the game number (in the URL) is appropriate for the MC's capabilities.

Review by cgiAlexis

Version reviewed: 0.5.3 on 07/28/2017

Still reading through the content, there's so much of it which is cool

Maybe though some text formatting or images could break up the flow once ArmyOfRobots gets to the end of creating content :)

It's definitely a part of the genre that's not been explored well between MC and TF and I'm glad that the creator here did such a good job of it, other artists on similar projects could probably play a little of this :)

Total Games: 1,223
Total Contests: 30
Total Reviews: 10,101
Total Engines: 30
Total Adult Themes: 9
Total Transformation Themes: 23
Total Multimedia Themes: 9
Total Online Plays: 1,953,111