The matches could be incredibly slow. You could start a match and go grab a snack and you'd still be alive. On the flip side if you died it could be 10+ minutes to respawn. Sound was really important. I think eventually you could tag enemies on a minimap, but we had a ton of abbreviations for calling out locations in chat. The weapons had their quirks too.
The training and qualifications were also hella tedious. Like to get medic qualified you had to sit through this classroom lecture and take a test. The special forces qualification (opened more levels and weapons) was also really tough.
I hopped on in a later update and it was just constant respawn like any modern FPS. Anyway, loved that game. Never joined the military but I thought about it.