Moving around using the [WASD] keys and aiming using the mouse, you'll wander across the surface of the planet fighting off aliens along the way. Your colonist is armed with a variety of weapons including pistols, rifles and rocket launchers, all of which do a great job of splattering aliens into goo. Standing still in an unexplored space will gradually dig it up, earning you resources that you can use to upgrade your base or build new items and equipment. There are several different resources, most of which are shared between upgrades, so you need to prioritize what you want and save up. Resources are also used to build rations and medical kits, which are necessary to keep your strength up as you explore.
Planet Noevo runs on a day and night cycle, and at night the aliens become much more prolific and aggressive so you need to hole up in your base until morning. You lose the game if your base is destroyed, but it's fairly good at defending itself with an automated turret so this isn't really an issue. Time passes quickly at night so this isn't as much of a pain as it could have been. Instead, it's a great time to upgrade your gear and level up.
Initially your character is fairly weak, but as you fight off aliens you gain experience points and level up. Each level earns you several stat points that you can use to upgrade various attributes, including speed, how much damage you deal with weapons and how quickly you dig up resources. You also gain experience for enemies killed by the automated turret on your base, which is a nice touch and helps keep night from feeling like a total waste of time.
There are two main gameplay modes in Planet Noevo. In Story Mode you're trying to survive for ten days, as mentioned earlier, while in Arcade Mode you're aiming to survive as long as you can. The former serves as a sort of tutorial for the latter, which is the real meat of the game.
Analysis: Planet Noevo has managed to nail the carrot-on-a-stick gameplay model. There's always another weapon upgrade or level just within reach, pushing the player to keep going for just another few minutes. The weapon types are varied enough to mix the game up, and resources come gradually enough that it feels like an accomplishment to build that new, shiny toy. All in all, this results in an addictive experience, but there's still a flaw or two.
First, and this is prominent enough that it bears mention before anything else, the final boss of Story Mode drastically ramps up the difficulty to such an extent that it casts a shadow on the rest of the game. Without the best available weapon and decent armor, this boss presents a nearly insurmountable challenge. It's possible to defeat on a second playthrough where the player knows which upgrades, gear and stats to aim for, but it's unlikely anyone will be ready to face it on their first time through the game. I'd recommend skipping the Story Mode entirely because of this and going straight to Arcade Mode, which is the same game without the 10-day time limit.
Also, the survival aspect of the game seems a bit tacked on. Ration resources used to make food are readily available and are only used for minor base upgrades otherwise, so the hunger meter serves as more of a "gotcha" if you forget to make food at night than anything else. It's not so much a source of anxiety as a source of annoyance. Likewise, the energy meter drains so slowly while exploring and is refilled so quickly in the base, even without upgrades, that it might as well not be there at all. Survival is an important part of the game's theme, so these gameplay elements are there for a reason, but it would've been nice if they had been better integrated into the experience.
These problems don't prevent Planet Noevo from being a solid casual experience. Despite the game's claims that it's complex and difficult to understand, it really boils down to a high quality arena shooter and defense game. Between combat, resource gathering and defense, there's plenty to enjoy here.