Taking it in order
2 stat system makes sense for a game this short. Sports and Smarts are good names for them too. Alliterative and fit the genre. Should probably put a bit about what they're for near this though I had to skim the rest of the doc to figure it out before continuing.
Architypes are perfect, and throwing Dog in there is icing on the cake. The advantages and disadvantages are a little confusing. Some of them have clear narrative/mechanical implications like a nerd and their glasses, rich kids having money, etc., but others like a jock being good at sports overlap with the stats you already outlined. If a jock is good at sports they should have a good sports score, not an ability that says they are. You could make a literal +1 bonus to that score or something, but I think the narrative abilities you have for some of them are more interesting. Maybe the jock can call in some guys from the football team for backup, but is quietly hated by all the nerds in the area.
The list of aliens are good, they all feel unique and would lead to very different games. I think ability/weakness might be a clearer name than advantage/disadvantage. Could use it for the architypes too. Some of the language like "Toxoplasma gondii" could be simplified.
Plot options are also good.
2d6 roll under feels right for this. I'm generally not a huge fan of roll systems with no mechanical way of adjusting difficulty, but I think this game is loose and lighthearted enough that it doesn't matter.
Crits on your number means that mathematically someone with a 6 or 7 sports is more likely to crit on a sports check than someone with 9 sports. I don't think it's a huge deal, but you could try doing a
"if you roll 4 under your score" system instead. You'd be about as likely to crit with a 6 or 7 stat, but would be more likely with higher stats than lower stats.
Cowering on a double 1 and overexerting on a double 6 feels backward for a roll under system.
Adding a d6 and choosing the best 2 is a very nice way to handle helping.
Alien Influence is a weird one. I like the abilities you've given the aliens for it, but it's never in the parties interest to take that 6th point. It's both mechanically brutal and means that player either needs to play villain or sit out. I think you could solve this by making the threat a little more open ended. The party adds to the pool collectively and at 6 alien influence something "really bad" happens. This might mean the Uvuuls mind control an important NPC, the Zetan reanimate a whole graveyard, or something else the GM thinks would be good on the fly.
GM advice is solid. Failing forward and a reminder to push the story in interesting directions is always good to include.
Plot twist table is great, love everything about it.
On the whole I think the biggest selling point to all this is the atmosphere. The game fits the genre really well, and the genre is fun as hell.
Viewing post in Invasion of the Third Kind (Two Page Demo) jam comments
Love the criticism, thank you. I did double check the first mention of Sports and Smarts in the doc and it does show what they are right there in the second step of character creation.
Love that you loved the Dog, we tested the game and the Dog is 100% the most overpowered archetype in the game while also being the hardest. As for the Jock's Advantage and Disadvantage being things that would appear to be a given, we treated all Advantages and Disadvantages as more a narrative tool than anything that offered a mechanical edge/hinderance. Even the Nerd losing their glasses was more to help build tension in a scene than something that added modifiers or stopped rolls. For the Jock we acutally used them to further the idea that the Jock would just innately be better at things using a Sports roll and could pull off more over the top actions than others, but would have trouble recalling how to tie his shoes.
The Alien races are still a bit in flux, originally the Krol had Chest Bursters for their influence but we changed it when we decided to push for an actual book and look for more aliens to add. The Toxoplasma Gondii wil be gone in the next patch of the two page to reflect their actual Influence.
And funny thing is, I was talking it over with my partner the other day and voiced my concern about the Overexertion/Lazy rolls being reversed and have wanted to flip it so having someone else voice a concern with it is going to have me so just that. It's one of those things that felt right in writing and when I played it, it felt wrong.
The intention of the Alien Influence being basically a get out of jail free card was to give players more agency over their rolls while increasing dramatic tension. In the playthrough, it worked. We never made it to six because the plot twist we rolled up converted our Jock into a Draqnal drone. I do need something for the 6th point that pushes it further but the limited length made it hard to fit something like that in. Right now, I'm thinking a last desperate attempt and maybe an auto crit. I want it to stay in line with that 80s alien invasion plot where people commonly give it everything knowing what will happen.
But overall, you've given me a lot to consider. I am working on an actual expansion of the game into an RPG akin to Luke Westaway's GravityRIP in terms of size and ability to be played beyond a single session. But I do want the two-page to be a solid and fun experience.
What I've been thinking is giving the Jock something like, "Big Damn Hero: You're an action star or hero in your own mind." for their Advantage and playing with the idea of them being too courageous for their own good. While their Disadvantage could be, "Despair in Defeat: You don't handle loss very well at all."
While I agree, all of the Advantages and Disadvantages are narrative to begin with and mone do anything mechanical even while playing. These are all used to add spice to a situation just like Big Damn Hero and Despair in Defeat. What they do during a game is more up to the interpretation of the GM and Players.