T-Rex Chrome Game — Rex Run

Rex Run: the dinosaur runner with room for a second jump

Rex Run is my Chrome dinosaur game remake, built solo with AI assistance from ChatGPT. The familiar jump-and-duck idea sits inside a 3D desert, with an animated green T-Rex, cacti, rocks and low-flying birds. It remains an endless runner: distance keeps increasing, and the run ends when an unprotected collision catches the dinosaur.

Adventure, Classic and a daily seed

Adventure allows two jumps before landing. It also places amber coins and power-ups along the trail. Classic removes those collectibles and abilities and allows one jump. Daily Trail uses the Adventure rules with a random seed based on the browser's local calendar date. It offers a repeatable starting seed for that day, rather than an online competitive leaderboard.

Speed rises with distance, and the environment cycles through three sky themes every 450 metres. Birds appear later in the run, adding a reason to duck as well as jump. The 500-metre challenge is a milestone to work toward, not the end of the trail.

Pickups change a short stretch of the run

Amber coins add 25 points each. A shield lasts up to eight seconds and is consumed by one collision. A magnet collects nearby amber for eight seconds. A six-second boost adds speed and doubles the distance points earned while it is active. The engine keeps those bonus points separately, so the score does not drop when the effect expires.

Press Space, Up or W to jump, then press again in the air for the second jump where the mode allows it. Hold Down or S to duck. Ducking while airborne accelerates the descent, which helps bring the dinosaur back down sooner. Touchscreens have Jump and Duck buttons. P or Esc pauses.

Animation alongside collision rules

The renderer uses Three.js 0.186.0. GLTFLoader loads Kenney Nature Kit scenery and Quaternius's rigged T-Rex; AnimationMixer plays the character's clips. The simulation uses small time steps and a shorter collision height when ducking on the ground, keeping the pose and obstacle rules connected. Best score, accumulated coins, achievements, recent runs and settings are stored locally. Rex Run joins the free Solo Game Devs collection, with a standalone HTML download planned.