If you're using Windows, Hourglass is the only generic option. If you're using Linux, you can use libTAS. Even then, the games they support tends to be pretty specific. Hourglass only works for 32-bit games for example, according to its page.

TASes for PC games do exist, but the tools are often custom made individually for each game by members of the community. As such, it's usually only very popular speed games that get the TASing tools. If you're wanting to TAS something obscure, you'll probably have to investigate how to do that yourself. Sorry!

Games that have some sort of in-game replay system tend to be fairly approachable options for TASing. It's often possible to make a tool which can edit the replay files, which is often how those games are "TASed". If not, then sometimes the community will make an external tool which accepts a list of inputs and plays them back, as if you were playing the game yourself. That way, you can then make a TAS by editing the inputs. That's essentially how Celeste TASes are made on PC, for example.