This game is a short but sweet throwback - it's cool what they do with the story choices on subsequent playthroughs, so definitely worth a few campaign runs if you enjoyed finishing the first run. I've done a couple playthroughs now and will defnitely be playing another and trying harder difficulties.
While there's some nuance to be found with the slide/roll invincibility to dodge projectiles and hazzards, and other evasive strategies, it doesn't go too much deeper than that. There's some variety and the game feels good to play though, it feels like there's good groundwork here for sequels to expand on it.
I'd be perfectly satisfied being ~£20 out of pocket for this game, considering it's my kinda genre and the T2 nostalgia factor, but like Fry said for most it may be more of a £10-£15 game.
If you liked this game I'd highly recommend
Huntdown, a great 16bit era hommage and although more challenging than T2 it's very checkpoint friendly with no game overs.
If familiar with these kinda games it's not especially difficult on Normal no, up until towards the end the levels and regular enemies are fairly easy. Some bosses can seem tricky at first but once you know their few mechanics and figure out how to deal with (or cheese) them, they're quite straightforward and don't require especially fast reactions. If you lose all your Continues it's back to the beginning, but it's rewarding to take what you learned into the next attempt.