Seems alright overall. Some thoughts:

Just make it +1 Str/+2 Con. Giving two meaningless options is unnecessary.

The rolling thing is cute. Can they roll uphill? I'd suggest forcing them to walk up inclines; that'll make some interesting tactical choices about how to approach enemies.

I don't really like damage immunities on player races, but I think it's unavoidable here.

Rocky Appearance is fine. How about stealing the Stonecunning template from dwarves? "Whenever you make a Dexterity (Stealth) check related to disguising yourself as a boulder, you are considered proficient in the Stealth skill and add double your proficiency bonus to the check, instead of your normal proficiency bonus."

The Charge template you cribbed from the Monster Manual is really built for NPCs, and gets way overpowered once you start thinking about classes that can make 3-4 attacks in a turn. Consider that you've basically given the character (A) an extra greatsword worth of damage and (B) the Trip Attack battlemaster maneuver, for free, on every attack.

So let's try to rein this in a little. Using the Charger feat and the Ravnica minotaur race as examples, how about something like this:

Rolling Charge. Immediately after you use the Dash action on your turn and move at least 20 feet, you can make one melee attack as a bonus action. If this attack hits, you gain a +5 bonus to the damage roll, and if it is an unarmed strike, you can attempt to knock the target to the ground.

The creature must be no more than one size larger than you and within 5 feet of you. It must make a Strength saving throw against a DC equal to 8 + your proficiency bonus + your Strength modifier. If it fails, it is knocked prone.
You'll notice that this is still quite powerful, and makes for a great opening move. I left the option to make a standard melee attack if you want, but the real use case is an unarmed strike with a big damage bonus that also knocks someone down.

Forcing the player to use a Dash and their bonus action to do this keeps it in the realm of "a tactical option you can use", rather than "the single best thing you could do every turn no matter what".