Neighbors has me hooked with the ideas of competitiveness and a future tournament(s). But for your other players, the mentally healthy ones, not me, there are a lot of things that can be their reason to play long term.
Keeping the game fun
Above all, if the game isn't fun, people aren't going to stick around. This is most important when taking into account new players, the plan to only match them against other new players is good. But that only covers the "balance" part, as they won't be getting trashed by much more experienced players. There are still a lot of bugs which can make the experience miserable. This point is something you all know as devs, but it's also the most obvious thing I couldn't have started this feedback without.
Below are actual suggestions
1. Competitive play
Adding a competitive mode achieves a few things:
- It separates the "sweats" from the "casuals", allowing people to enjoy the game in whichever environment they prefer
- It creates a long term goal, depending on the rewards, that the competitive players will grind for. I'll come back to this later
- It allows experienced players to show off their skill while giving them interesting games, not just one sided stomps
But it also creates some potential problems:
- Splitting the playerbase. Now the players have 2 modes to queue up for instead of just 1. Especially with early access' low playercount this means longer queue times for both modes. Mainly for the competitive one as the casual one I assume will still be more popular
- META and toxicity. Competitive players love optimizing games. This doesn't have to be bad but it's often the case that players get upset, sometimes reasonably so, when someone just starting out with comp, plays in an "undesired" way, blaming that person for a loss

