whats it like to build a game with alot of other people?

It feels amazing to be part of such thing, many people with same passion and enthusiasm, working on creating their passion and fantasy into reality.

The primary difference between a small team and a large team is that you would be assigned a more particular or specialized task or area to work on. For example, in a small team, you will be wearing multiple hats depending on what your team is lacking. You can be an engineer most of the time, but have to be the designer sometimes, and a tester other times. In a large team, you would usually only be assigned a particular area or even individual specific game systems or features. Also, in a large team, you will likely need to collaborate a lot more with different teams within, and need leads approvals to do things.

Being in a small team has the perk of gaining experience in multiple areas, and make your own decisions on the game a lot of times. However, being in a big team, you get to be part of something much larger than you can imagine, and the support you get from tens and hundreds of years of experience from others is amazing. There're trade offs. I've been on both types. I recommend everyone to try both.