Often available for ~$9.99, though it frequently goes on sale.
You can also find Steam activation keys at stores like Fanatical or G2A . Dino d-day Download PC Game
While primarily a multiplayer experience with modes like Team Deathmatch and King of the Hill, you can play offline with bots if servers are quiet. Often available for ~$9
The game uses Valve's Source Engine and has relatively low requirements, making it playable on older hardware or laptops. Minimum Requirement Windows XP / Vista / 7 Processor 3.0 GHz P4, Dual Core 2.0, or AMD64X2 Memory Graphics Often available for ~$9.99