I suggest tentacle planets being a planect infected with a terrible host. There could be different levels of maturity of the host giving higher or lower difficulty to the planet. A very young host for example, would be inside only and would have not deveoped tentacles, while a fully developed host will have tentacles strong enought to trap your ship if you get too close to the planet. Once you get into an underground area of the planet controlled by the host (you have to pass through host flesh) enemies will be either some geometrical patterns or mimics of living creatures assimilated by the host. If you go to a mature host planet, you'll have to at least weaken the host to get it to release your ship, for this there could e several options - Doing enought damage to the host so that it releases your ship. That would involve getting inside the host, fighting its defenses and damaging the flesh. With this option, your ship would have a chance to be infected by the host, eventually infecting other planets you visit. - Through science eventually unlocking different tools -Terraforming the planet causing it to freeze, this will not destroy the host or remain for long, but will allow you to escape without landing on the planet surface. - Eventually through a minor side quest, developing a virus that can destroy the host. This would need you to eventually get to the host core and plant the virus there, perhaps the host could have several cores making it a greater chore.
I'm curious to see what they do with the tentacle biome. I was a little disappointed when I "chopped down" a tentacle, and the pieces yielded "Unrefined wood" ...I suspect that is a placeholder. I would like it very much if the tentacles were more a stationary NPC than a 'tree' - it would whip around and such, and you'd have to shoot it down, not chop it down (unless you're using a sword ), with the planet as a whole ultimately being a boss - clear the tentacleso n the surface, then proceed underground and do some damage to more tentacles or like-growths, then proceed to the core and have a nice boss fight. ...they've gotta have *something* planned.
