3 just feels a little more polished than 4. The transition to 3D was very cool but I think the developer’s inexperience with working in 3D hurt the game a little. Plus 3 has a lot more user content than 4 due to being much older. They are both very good games regardless!
Creeper World is sort of like this. Basically the enemy is a self replicating liquid that destroys everything it touches and you have to fight it off and secure each map. It was originally a flash game so go with those expectations but it’s pretty fun regardless. I recommend CW3 as the best one.
Here’s one that most of you have probably not heard of. Monster Hunter Frontier.
MHF was a Monster Hunter MMO that ran from 2007 to 2019 and was exclusive to Asia. Recently, a dedicated team of community members have managed to revive it with community servers.
It is brutally difficult, only partially translated, and has some genuinely awful controls, BUT
It’s only around 6GB and completely free.
If for some reason you want to try it I highly recommend joining the rain server, as it is the most populated and stable one. They also have a setup guide for how to install on their discord server I recommend you use.